Method and apparatus for transmitting and receiving broadcast signal for providing trick play service

ABSTRACT

A method and apparatus for transmitting and receiving a broadcast signal for a trick play are disclosed. The broadcast signal transmitting method includes encoding video data to create a video elementary stream (ES), creating a packetized elementary stream (PES) including the video elementary stream (ES), creating a transport stream (TS) including the created PES, wherein the TS includes PVR assist information for executing a trick play, the PVR assist information includes tier number information and maximum temporal identification information, and the tier number information indicates a tier number having a value obtained by adding 1 to a temporal identification information value of a picture different from a RAP picture and the maximum temporal identification information indicates a maximum temporal identification information value of the video elementary stream (ES) including the encoded video data, and transmitting the created TS.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of PCT International ApplicationNo. PCT/KR2014/011042, filed on Nov. 18, 2014, which claims priorityunder 35 U.S.C. 119(e) to U.S. Provisional Application Nos. 61/910,416filed on Dec. 1, 2013, 61/952,140 filed on Mar. 13, 2014, 61/954,615filed on Mar. 18, 2014 and 61/970,910 filed on Mar. 27, 2014, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

TECHNICAL FIELD

The present invention relates to transmission and reception of abroadcast signal. More particularly, the present invention relates to amethod and apparatus for transmitting and receiving a broadcast signalfor providing a trick play service.

BACKGROUND ART

In recent years, demand for and interest in a high-resolution,high-quality image service is very high. As an ultra high definition TV(UHDTV) following a HDTV has come into the market, a very realistichigh-resolution, high-quality broadcast service is being provided. In amobile market, a smart phone having an HD level basic screen resolutionhas also come into the market and, as a result, users' demand for ahigh-resolution, high-quality image is rapidly increasing.H.264/advanced video coding (AVC) standards used now in variousmultimedia devices, such as a DTV, a DMB, a DVD, a digital camcorder, animage black box, an IPTV, a smart TV, and a smart phone, are limited insupporting a high-resolution, high-quality image service. For thisreason, ITU-T Video Coding Experts Group (VCEG) and ISO/IEC MovingPicture Experts Group (MPEG) have started to standardize high efficiencyvideo coding (HEVC) according to the necessity of a new next generationmoving picture compression standard having a higher compression rate anda lower complexity than H.264/AVC and completed Final DraftInternational Standard (FDIS) of HEVC. HEVC is a next generation imagecompression standard exhibiting coding efficiency equivalent to about35% that of H.264/AVC and has attracted considerable attention as a coretechnology for effectively compressing huge data of HD level images andUHD level images. It is prospected that optimized HEVC software andhardware standards will come into the market through efforts forcommercialization of HEVC technology all over the world.

Meanwhile, a trick play means a service providing a function that iscapable of reproducing an image after a random time, i.e. enablingrandom access, and an X speed function, such as an X2 speed and an X4speed. Since there is a difference between a random access point of HEVCand a random access point of H.264, it is necessary to newly define acategory of the random access point of HEVC. In addition, HEVC providesscalability and, therefore, it is necessary to provide a trick playusing the same. Furthermore, a conventional CFF media file formatspecification defines a format for a trick play of H.264/AVC. However,content encoded by HEVC is not defined. Consequently, it is necessary toprovide a new format for decoding and a trick play of content encoded byHEVC.

For execution of a trick play, pictures constituting a video stream areclassified using a concept of a tier according to dependency between therespective pictures in a conventional AVC/H.264 base. A receiving sidedecodes and displays only pictures having a specific tier value toprovide a trick play. Since HEVC basically provides temporal scalabilityof a video stream, however, it is necessary to study a method ofproviding a trick play service using temporal scalability. Moreover, ifa user knows providable maximum X speed information, the user may feelconvenience in using a trick play. Consequently, it is necessary tostudy a method of providing providable maximum X speed information tothe user.

DISCLOSURE Technical Problem

An object of the present invention devised to solve the problem lies ona method and/or apparatus for transmitting and receiving a broadcastsignal for providing a trick play service.

Another object of the present invention devised to solve the problemlies on information related to a trick play for providing a trick playservice.

Another object of the present invention devised to solve the problemlies on a method of signaling information related to a trick play.

Another object of the present invention devised to solve the problemlies on a signaling method that is capable of providing maximum X speedinformation to a user.

Another object of the present invention devised to solve the problemlies on a method of providing a trick play using temporal scalabilitybasically provided by HEVC.

A further object of the present invention devised to solve the problemlies on a method of providing a better trick play service whilemaximally using conventional information related to a trick play as itis.

Technical Solution

The object of the present invention can be achieved by providing abroadcast signal transmitting method including encoding video data tocreate a video elementary stream (ES), creating a packetized elementarystream (PES) including the video elementary stream (ES), creating atransport stream (TS) including the created PES, wherein the TS includesPVR assist information for executing a trick play, the PVR assistinformation includes tier number information and maximum temporalidentification information, and the tier number information indicates atier number having a value obtained by adding 1 to a temporalidentification information value of a picture different from a RAPpicture and the maximum temporal identification information indicates amaximum temporal identification information value of the videoelementary stream (ES) including the encoded video data, andtransmitting the created TS.

The tier number indicated by the tier number information may have avalue of 0 for the RAP picture.

The maximum temporal identification information may be used to provideinformation regarding speed of the trick play.

The PVR assist information may be included in an adaptation field of theTS.

The PVR assist information may include segmentation info flaginformation indicating existence or nonexistence of informationregarding a segment to which a picture belongs.

The PVR assist information may include segment identifier informationindicating an id of a segment to which a picture belongs.

The PVR assist information may include program identifier informationindicating an id of a program to which a picture belongs.

The PVR assist information may include at least one selected frombetween segment start flag information for identifying a picture havinga first presentation order in each segment and segment end flaginformation for identifying a picture having a last presentation orderin each segment.

The PVR assist information may include at least one selected frombetween program start flag information for identifying a picture havinga first presentation order in each program and program end flaginformation for identifying a picture having a last presentation orderin each program.

In another aspect of the present invention, provided herein is abroadcast signal receiving apparatus including a tuner for receiving atransport stream (TS), wherein the TS includes PVR assist informationfor executing a trick play, the PVR assist information includes tiernumber information and maximum temporal identification information, andthe tier number information indicates a tier number having a valueobtained by adding 1 to a temporal identification information value of apicture different from a RAP picture and the maximum temporalidentification information indicates a maximum temporal identificationinformation value of a video elementary stream (ES) including encodedvideo data, a first extraction unit for extracting a packetizedelementary stream (PES) from the received TS, a second extraction unitfor extracting a video elementary stream (ES) from the extracted PES,and a decoder for decoding the extracted video elementary stream (ES).

The tier number indicated by the tier number information may have avalue of 0 for the RAP picture.

The maximum temporal identification information may be used to provideinformation regarding speed of the trick play.

The PVR assist information may be included in an adaptation field of theTS.

The PVR assist information may include segmentation info flaginformation indicating existence or nonexistence of informationregarding a segment to which a picture belongs.

The PVR assist information may include segment identifier informationindicating an id of a segment to which a picture belongs.

The PVR assist information may include program identifier informationindicating an id of a program to which a picture belongs.

The PVR assist information may include at least one selected frombetween segment start flag information for identifying a picture havinga first presentation order in each segment and segment end flaginformation for identifying a picture having a last presentation orderin each segment.

The PVR assist information may include at least one selected frombetween program start flag information for identifying a picture havinga first presentation order in each program and program end flaginformation for identifying a picture having a last presentation orderin each program.

Advantageous Effects

The present invention has the effect of providing a trick play serviceto a user.

The present invention has the effect of providing information related toa trick play for providing a trick play service to a user.

The present invention has the effect of providing a method of signalingproviding information related to a trick play to a user.

The present invention has the effect of providing providable maximum Xspeed information to a user in a trick play service.

The present invention has the effect of providing a more efficient trickplay service using temporal scalability of HEVC.

The present invention has the effect of providing a more efficient trickplay service while maximally maintaining a conventional system relatedto a trick play service.

The present invention has the effect of providing a trick play serviceusing the structure of an HEVC video stream as it is.

The present invention has the effect of providing a trick play serviceusing a temporal ID-based structure of an HEVC video stream, therebyproviding a higher encoding speed without necessity of signaling aspecific picture which will be used in a trick play at an encoding step.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing a trick play method according to an embodimentof the present invention based on scenarios.

FIG. 2 is a view showing a Common File Format (CFF) box structure forsupporting an HEVC-based stream according to an embodiment of thepresent invention.

FIG. 3 is a view showing syntax of an “hvcn” box according to anembodiment of the present invention.

FIG. 4 is a view showing an element supporting a High Dynamic Range(HDR) included in Common_Metadata according to an embodiment of thepresent invention.

FIG. 5 is a view showing a picture type for random access in a case ofan HEVC stream according to an embodiment of the present invention.

FIG. 6 is a view showing a trick play method in a case of a closed GOPaccording to an embodiment of the present invention (scenario 1-1).

FIG. 7 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a decodable leading picture according to anembodiment of the present invention (scenario 1-2).

FIG. 8 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a decodable leading picture and a skippedleading picture according to an embodiment of the present invention(scenario 1-2).

FIG. 9 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a skipped leading picture according to anembodiment of the present invention (scenario 1-2).

FIG. 10 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0according to an embodiment of the present invention (scenario 1-2).

FIG. 11 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0according to another embodiment of the present invention (scenario 1-2).

FIG. 12 is a view showing the description of pic_type included in atrick play box for supporting a trick play of an HEVC stream having amax_temporal_id of 0 according to an embodiment of the presentinvention.

FIG. 13 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0in a case in which pic_type does not include contents related to aleading picture according to an embodiment of the present invention(scenario 1-1).

FIG. 14 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0in a case in which pic_type does not include contents related to aleading picture according to another embodiment of the present invention(scenario 1-1).

FIG. 15 is a view showing the configuration of an HEVC stream supportingtemporal scalability according to an embodiment of the presentinvention.

FIG. 16 is a view showing the configuration of a trick play box forrestricting the maximum X speed to support a trick play in an HEVCstream supporting temporal scalability according to an embodiment of thepresent invention (scenario 2).

FIG. 17 is a view showing the configuration of a trick play box forrestricting the maximum X speed to support a trick play in an HEVCstream supporting temporal scalability according to another embodimentof the present invention (scenario 2).

FIG. 18 is a view showing a frame rate changing method in a case inwhich a temporal sub-layer picture type is TSA according to anembodiment of the present invention.

FIG. 19 is a view showing a frame rate changing method in a case inwhich a temporal sub-layer picture type is STSA according to anembodiment of the present invention (scenario 3).

FIG. 20 is a view showing the configuration of a trick play box forsupporting a high X speed trick play in an HEVC stream supportingtemporal scalability according to an embodiment of the present invention(scenario 3).

FIG. 21 is a view showing the configuration of a trick play box forsupporting a high X speed trick play in an HEVC stream supportingtemporal scalability according to another embodiment of the presentinvention.

FIG. 22 is a view showing the structure of a broadcast signal receivingsystem according to an embodiment of the present invention.

FIG. 23 is a view showing the structure of a receiving end according toan embodiment of the present invention.

FIG. 24 is a view showing a trick play method compositively using atemporal id and a tier according to an embodiment of the presentinvention.

FIG. 25 is a view showing a trick play method based on a conventionaltier concept according to an embodiment of the present invention.

FIG. 26 is a view showing a trick play method based on a method ofmapping one temporal id to one tier one to one according to anembodiment of the present invention (scenario A-a).

FIG. 27 is a view showing a trick play method based on a method ofmapping one temporal id to one tier one to one according to anotherembodiment of the present invention (scenario A-a).

FIG. 28 is a view showing a result of mapping one temporal id to onetier one to one according to an embodiment of the present invention.

FIG. 29 is a view showing a result of mapping one temporal id to onetier one to one according to another embodiment of the presentinvention.

FIG. 30 is a view showing a trick play method based on a method ofmapping one temporal id to several tiers according to an embodiment ofthe present invention (scenario A-b).

FIG. 31 is a view showing the configuration of an adaptation field of aTS packet including information for mapping of a temporal id and a tieraccording to an embodiment of the present invention.

FIG. 32 is a view showing the configuration ofHEVC_temporal_id_tier_mapping_info according to an embodiment of thepresent invention.

FIG. 33 is a view showing the configuration of a trick_play_speed fieldincluded in HEVC_temporal_id_tier_mapping_info according to anembodiment of the present invention.

FIG. 34 is a view showing the configuration of PVR_assist_informationaccording to an embodiment of the present invention.

FIG. 35 is a view showing the configuration of PVR_assist_informationhaving a temporal id frame work added thereto according to an embodimentof the present invention (scenario B-a-a).

FIG. 36 is a view showing the configuration of PVR assist informationhaving a temporal id frame work added thereto according to anotherembodiment of the present invention (scenario B-a-b).

FIG. 37 is a view showing the configuration of PVR_assist_informationfor supporting a trick play using a temporal id according to anembodiment of the present invention (scenario B-b).

FIG. 38 is a view showing a receiving apparatus according to anembodiment of the present invention.

FIG. 39 is a view showing comparison between a tier framework and anHEVC temporal sub-layer according to an embodiment of the presentinvention.

FIG. 40 is a view showing the configuration of PVR_assist_informationaccording to another embodiment of the present invention.

FIG. 41 is a view showing a trick play method using an HEVC temporalsub-layer according to an embodiment of the present invention.

FIG. 42 is a view showing a broadcast signal transmitting methodaccording to an embodiment of the present invention.

FIG. 43 is a view showing the structure of a broadcast signal receivingapparatus according to an embodiment of the present invention.

BEST MODE

Reference will now be made in detail to the preferred embodiments,examples of which are illustrated in the accompanying drawings. Itshould be noted herein that these embodiments are only for illustrativepurposes and the protection scope of the present specification is notlimited or restricted thereto.

Terms used in present specification are general terms selected inconsideration of functions and widely used at the present time. However,such terms may vary depending upon intentions of those skilled in theart to which the present specification pertains, usual practices, orappearance of new technology. In a specific case, some terms may beselected by the applicant of the present application. In this case,meanings of such terms will be described in corresponding paragraphs ofpresent specification. Therefore, it should be noted that terms used inpresent specification be interpreted based on real meanings of the termsand the present specification, not simple names of the terms.

For easy understanding of the present invention and the convenience ofdescription, terms and abbreviations are defined as follows.

High Efficiency Video Coding (HEVC) is a high efficiency video codingstandard providing the same video quality as a conventional H.265/AVCtechnology while having a compression rate about twice higher than thatof the H.265/AVC technology.

Temporal scalability means a method of coding frames having differentframe frequencies in the same spatial resolution

A trick play means a function that is capable of reproducing an imageafter a random time, i.e. enabling random access, and providing an Xspeed function.

An Open GOP means a structure that is capable of encoding a picture inone GOP using a picture located before the corresponding GOP as areference picture, i.e. an GOP including a leading picture.

A Closed GOP means a structure for encoding a picture in one GOP usingonly a picture in the corresponding GOP as a reference picture, i.e. anGOP not including a leading picture unlike the Open GOP.

The leading picture means a picture in HEVC having a later decodingorder but an earlier reproduction order than IRAP.

Temporal id is a term introduced to support temporal scalability in HEVCand may be signaled by nuh_temporal_id_plus1 of NAL_unit_header.

Tier is a term introduced to support a trick play in an AVC stream or anmpeg-2 stream and may be included in an adaptation field in a TS packet.

FIG. 1 is a view showing a trick play method according to an embodimentof the present invention based on scenarios.

According to an embodiment of the present invention, a signaling methodfor a trick play may be defined based on whether to use temporalscalability of HEVC.

In a case in which a video stream according to an embodiment of thepresent invention is a stream which does not provide temporalscalability, i.e. in a case in which the video stream includes only apicture having a temporal_id of 0, for a Closed GOP, dependency_leveland pic_type defined in a CFF media file format may be signaled toprovide a trick play since the video stream does not include a leadingpicture (scenario 1-1). On the other hand, for an Open GOP, leadingpicture type may be included in pic_type and dependency_level may besignaled to provide a trick play (scenario 1-2).

In a case in which a video stream according to an embodiment of thepresent invention is a stream based on temporal scalability, i.e. in acase in which the video stream includes a picture having a temporal_idof more than 0, dependency_level, pic_type, andtemporal_sub_layer_pic_type may be signaled to provide a trick play.More specifically, a supportable speed level may be signaled throughtemporal_id included in the stream to provide a trick play (scenario 2).In addition, a supportable X speed level may be signaled throughtemporal_id in the same manner as in scenario 2 and a picture having atemporal_id of 0 may be additionally used to provide an additionalservice for X speed (scenario 3).

A box shown in this figure may indicate a picture constituting a videostream and T_ID described in the box may mean temporal_id for supportingtemporal scalability.

FIG. 2 is a view showing a Common File Format (CFF) box structure forsupporting an HEVC-based stream according to an embodiment of thepresent invention.

In this figure, NL0″, “NL1”, and “NL2” may indicate an inclusionrelationship of CFF boxes, “Format Req.” may indicate existence ornonexistence of corresponding boxes and the number of the correspondingboxes, “Specification” may indicate a portion of standards defining thecorresponding boxes, and “Description” may indicate the description ofthe corresponding boxes. In a case in which “Format Req.” is “+”, it maymean that one or more corresponding boxes exist. In a case in which“Format Req.” is “0/1”, it may mean that a corresponding box exists ordoes not exist. In a case in which “Format Req.” is “1”, it may meanthat a corresponding box exists. In a case in which “Format Req.” is“0”, it may mean that a corresponding box does not exist.

This figure shows a CFF box structure according to an embodiment of thepresent invention in which a new trick play box for HEVC is added to aconventional CFF. In addition, a CFF box structure according to anembodiment of the present invention may include a storage boxabbreviated to “hvcn” for supporting an HEVC-based nal unit.

FIG. 3 is a view showing syntax of an “hvcn” box according to anembodiment of the present invention.

According to an embodiment of the present invention, a CFF box structuremay include a nal unit storage box abbreviated to “hvcn”.

According to an embodiment of the present invention, the nal unitstorage box may be defined per codec for a trick play.

According to an embodiment of the present invention, the nal unitstorage box may not be defined per codec for a trick play and a HEVCtrick box different from a conventional AVC trick box may be defined ina conventional “trick” box. In addition, AVC or a HEVC trick play may beselected according to a flag of the “trick” box.

In this figure, HEVCConfig may include a Sequence Parameter Set (SPS)and a Picture Parameter Set (PPS) of HEVC and video information, such asa VUI parameter, of the SPS.

FIG. 4 is a view showing an element supporting a High Dynamic Range(HDR) included in Common_Metadata according to an embodiment of thepresent invention.

Common_Metadata referred to by an xml box according to an embodiment ofthe present invention may include a HighDynamicRange element.

A HighDynamicRange element according to an embodiment of the presentinvention may have a value of string according to an xml schema. OneHighDynamicRange element may exist or no HighDynamicRange element mayexist.

A HighDynamicRange element according to an embodiment of the presentinvention may indicate the minimum luminance and/or the maximumluminance (min.luminance and/or max.luminance).

A HighDynamicRange element according to an embodiment of the presentinvention may profile values classified by the minimum luminance and/orthe maximum luminance. For example, the HighDynamicRange element mayindicate Conventional capacity (min: 0.1 cd/m2, max: 100 cd/m2), Midcapacity (min: 0.001 cd/m2, max: 1000 cd/m2), or High capacity (min:0.0001 cd/m2, max: 10000 cd/m2).

FIG. 5 is a view showing a picture type for random access in a case ofan HEVC stream according to an embodiment of the present invention.

This figure shows a picture type which may be the base for random accessand execution of a trick play among HEVC NAL unit types.

A shaded picture type (TSA, STSA) in this figure may indicate an HEVCtemporal sub-layer picture type which may be used for a trick play in acase in which a stream having a temporal ID of more than 0 is included,i.e. temporal scalability is provided. The shaded picture type may beused scenarios 2 and 3 according to an embodiment of the presentinvention.

According to an embodiment of the present invention, random access pointpictures may include an Instantaneous Decoding Refresh (IDR) picture, aBroken Link Access (BLA) picture, and/or a Clean Random Access (CRA)picture, leading pictures may include a Random Access Decodable Leading(RADL) picture and/or a Random Access Skipped Leading (RASL) picture,and temporal sub-layer access pictures may include a Temporal Sub-layerAccess (TSA) picture and/or a Step-wise Temporal Sub-layer Access (STSA)picture.

The Instantaneous Decoding Refresh (IDR) picture may include a case inwhich the IDR picture has a related leading picture and/or a case inwhich the IDR picture does not have a related leading picture.

The Broken Link Access (BLA) picture may include a case in which the BLApicture has a related RADL picture but does not have a related RASLpicture and/or a case in which the BLA picture does not have a relatedleading picture.

The Clean Random Access (CRA) picture may include a case in which theCRA picture has a related leading picture.

The Temporal Sub-layer Access (TSA) picture may include a case in whichthe TSA picture is not referred to by the same sub-layer and/or a casein which the TSA picture is referred to by the same sub-layer.

The Step-wise Temporal Sub-layer Access (STSA) picture may include acase in which the STSA picture is not referred to by the same sub-layerand/or a case in which the STSA picture is referred to by the samesub-layer.

FIG. 6 is a view showing a trick play method in a case of a closed GOPaccording to an embodiment of the present invention (scenario 1-1).

This figure shows a method of executing a trick play in a case in whicha maximum temporal_id in a video stream is 0 and in a case of a closedGOP. A GOP is short for a Group Of Pictures and indicates a group ofcoded pictures for enabling random access. A closed GOP may mean a GIOPwhich does not include a leading picture and an Open GOP may mean a GIOPwhich includes a leading picture. The leading picture may indicate apicture in HEVC having a later decoding order but an earlier displayorder than an Intra Random Access Point (TRAP) (the same concept as arandom access point in AVC codec).

In this figure, one quadrilateral box may indicate one picture. Apicture may be used as the same meaning as a frame and/or an image.

In this figure, a group of pictures I1 to P9 may indicate one GOP.Picture I, which is one of three picture types used for a MPEG codingsignal, may include all data constituting one complete picture. That is,picture I may not refer to other pictures. Picture P may include only adifference value between estimated information obtained by observing adifference between a current picture and the previous picture inpresentation order and real information. That is, picture P may refer toa picture existing before a current picture in presentation order.Picture B may include only estimated information obtained by observing adifference among a current picture, the previous picture, and the nextpicture in presentation order. That is, picture B may refer to picturesexisting before and after a current picture. Arrows indicated in thisfigure may indicate reference among pictures. For example, picture B3may refer to picture I1 and picture B5 to make a complete picture andpicture P9 may refer to picture I1.

In this figure, numbers in the boxes may indicate a dependency_level ofeach picture. For example, a first picture may indicate a picture havinga dependency_level of 1, a second picture may indicate a picture havinga dependency_level of 5, and a third picture may indicate a picturehaving a dependency_level of 4.

According to an embodiment of the present invention, an X2 speed trickplay may be executed by decoding pictures having a dependency_levelvalue of 1 to 4. An X4 speed trick play may be executed by decodingpictures having a dependency_level value of 1 to 3. An X8 speed trickplay may be executed by decoding pictures having a dependency_levelvalue of 1 or 2. An X16 speed trick play may be executed by decodingpictures having a dependency_level value of 1.

FIG. 7 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a decodable leading picture according to anembodiment of the present invention (scenario 1-2).

A first figure part shows a decoding order of pictures constituting avideo stream, a second figure part shows a display order of picturesconstituting a video stream at a normal X speed, and a third figure partshows a display order of pictures constituting a video stream duringexecution of an X2 speed trick play.

In the second figure part, marked pictures B0 to B6 may indicate adecodable leading picture.

Since the leading picture included in the GOP is a decodable leadingpicture in this figure, pictures may be displayed from a portionindicated by an arrow as shown in the second figure part and a trickplay may be executed as shown in the third figure part. In a case inwhich an X2 speed trick play is executed, pictures B1, B3, B5, RAP, andB1 may be displayed according to a dependency_level of each picture asshown in the figure. A decodable leading picture may include a RandomAccess Decodable Leading (RADL) picture.

FIG. 8 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a decodable leading picture and a skippedleading picture according to an embodiment of the present invention(scenario 1-2).

A first figure part shows a decoding order of pictures constituting avideo stream, a second figure part shows a display order of picturesconstituting a video stream at a normal X speed, and a third figure partshows a display order of pictures constituting a video stream duringexecution of an X2 speed trick play.

In the second and third figure parts, marked pictures B0 to B2 mayindicate a skipped leading picture and marked pictures B3 to B6 mayindicate a decodable leading picture.

In this figure, a skipped leading picture may not be displayed and atrick play may not be executed. Consequently, pictures may be displayedfrom picture B3 as shown in the second figure part and a trick play maybe executed from picture B3 as shown in the third figure part. In a casein which an X2 speed trick play is executed, pictures B3, B5, RAP, andB1 may be displayed according to a dependency_level of each picture asshown in the figure. A decodable leading picture may include a RandomAccess Decodable Leading (RADL) picture and a skipped leading picturemay include a Random Access Skipped Leading (RASL) picture.

FIG. 9 is a view showing a trick play method in a case of an open GOPwherein the GOP includes a skipped leading picture according to anembodiment of the present invention (scenario 1-2).

A first figure part shows a decoding order of pictures constituting avideo stream, a second figure part shows a display order of picturesconstituting a video stream at a normal X speed, and a third figure partshows a display order of pictures constituting a video stream duringexecution of an X2 speed trick play.

In the second and third figure parts, marked pictures B0 to B6 mayindicate a skipped leading picture.

In this figure, a skipped leading picture may not be displayed and atrick play may not be executed. Consequently, pictures may be displayedfrom picture RAP as shown in the second figure part and pictures RAP andB1 may be displayed as shown in the third figure part in a case in whichan X2 speed trick play is executed. A skipped leading picture mayinclude a Random Access Skipped Leading (RASL) picture.

FIG. 10 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0according to an embodiment of the present invention (scenario 1-2).

This figure shows a signaling method of a trick play box for executing atrick play of a stream having a maximum temporal_id of 0.

According to an embodiment of the present invention, a new box “trikhvc”may be defined. A trikhvc box according to an embodiment of the presentinvention may include a pic_type field and/or a dependency_level fieldin a for loop repeated by a value of sample_count.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. The pic_type field may indicate a value of 4 bits.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 6 bits.

FIG. 11 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0according to another embodiment of the present invention (scenario 1-2).

This figure shows a signaling method of a trick play box for executing atrick play of a stream having a maximum temporal_id of 0.

According to an embodiment of the present invention, a trick play of anHEVC stream may be executed using a conventionally defined box “trik”.According to an embodiment of the present invention, an AVC or HEVCtrick play may be selected using a flag.

A trik box according to an embodiment of the present invention maydivide and signal a stream based on video codec using a flag. Inaddition, the trik box may include a pic_type field and/or adependency_level field in a for loop repeated by a sample_count value.

In a case in which a value of flag according to an embodiment of thepresent invention is 0, the trik box may signal an H.264/AVC trick play.In a case in which a value of flag is 1, the trik box may signal an HEVCtrick play.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. In a case in which a value of flag according to an embodimentof the present invention is 0, the pic_type field may indicate a valueof 2 bits. In a case in which a value of flag is 1, the pic_type fieldmay indicate a value of 4 bits.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 6 bits.

FIG. 12 is a view showing the description of pic_type included in atrick play box for supporting a trick play of an HEVC stream having amax_temporal_id of 0 according to an embodiment of the presentinvention.

Pic_type according to an embodiment of the present invention may have avalue of 0 to 15.

In a case in which a value of pic_type is 0, pic_type may indicate anIDR picture which does not have a related leading picture. In this case,nal_unit_type may indicate IDR_N_LP.

In a case in which a value of pic_type is 1, pic_type may indicate anIDR picture which has a related decodable leading picture. In this case,nal_unit_type may indicate IDR_W_RADL.

In a case in which a value of pic_type is 2, pic_type may indicate a BLApicture which has a related leading picture. In this case, nal_unit_typemay indicate BLA_N_LP.

In a case in which a value of pic_type is 3, pic_type may indicate a BLApicture which has a related RADL picture but does not have a relatedRASL picture. In this case, nal_unit_type may indicate BLA_W_RADL.

In a case in which a value of pic_type is 4, pic_type may indicate a BLApicture which has a related RADL picture and a related RASL picture. Inthis case, nal_unit_type may indicate BLA_W_LP.

In a case in which a value of pic_type is 5, pic_type may indicate a CRApicture which has a related leading picture. In this case, nal_unit_typemay indicate CRA_NUT.

In a case in which a value of pic_type is 7, pic_type may indicate aRandom Access Decodable Leading (RADL) picture. In this case,nal_unit_type may indicate RADL_N or RADL_R.

In a case in which a value of pic_type is 8, pic_type may indicate aRandom Access Skipped Leading (RASL) picture. In this case,nal_unit_type may indicate RASL_N or RASL_R.

In a case in which a value of pic_type is 9, pic_type may indicateundecided picture I.

A value of pic_type 10 may correspond to an unknown value.

Values of pic_type 11 to 15 may correspond to reserved values.

FIG. 13 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0in a case in which pic_type does not include contents related to aleading picture according to an embodiment of the present invention(scenario 1-1).

This figure shows a signaling method of a trick play box for executing atrick play of a stream having a maximum temporal_id of 0.

According to an embodiment of the present invention, a new box “trikhvc”may be defined. A trikhvc box according to an embodiment of the presentinvention may include a pic_type field and/or a dependency_level fieldin a for loop repeated by a sample_count value.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. The pic_type field may indicate a value of 3 bits.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 5 bits.

FIG. 14 is a view showing the configuration of a trick play box forsupporting a trick play of an HEVC stream having a max_temporal_id of 0in a case in which pic_type does not include contents related to aleading picture according to another embodiment of the present invention(scenario 1-1).

This figure shows a signaling method of a trick play box for executing atrick play of a stream having a maximum temporal_id of 0.

According to an embodiment of the present invention, a trick play of anHEVC stream may be executed using a conventionally defined box “trik”.According to an embodiment of the present invention, an AVC or HEVCtrick play may be selected using a flag.

A trik box according to an embodiment of the present invention mayinclude a pic_type field and/or a dependency_level field in a for looprepeated by a value of flag and sample_count.

In a case in which a value of flag according to an embodiment of thepresent invention is 0, the trik box may signal an H.264/AVC trick play.In a case in which a value of flag is 1, the trik box may signal an HEVCtrick play.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. In a case in which a value of flag according to an embodimentof the present invention is 0, the pic_type field may indicate a valueof 2 bits. In a case in which a value of flag is 1, the pic_type fieldmay indicate a value of 3 bits.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. In a case in which a value of flag according to anembodiment of the present invention is 0, the dependency_level field mayindicate a value of 6 bits. In a case in which a value of flag is 1, thedependency_level field may indicate a value of 5 bits.

According to another embodiment of the present invention, pic_type maybe configured as follows in a case in which a limitation that a leadingpicture is not displayed during execution of a trick play is included.In a case in which a value of pic_type is 0, pic_type may indicate thata corresponding sample is an unknown sample. In a case in which a valueof pic_type is 1, pic_type may indicate that a corresponding sample isan IDR sample. In a case in which a value of pic_type is 2, pic_type mayindicate that a corresponding sample is a CRA sample. In a case in whicha value of pic_type is 3, pic_type may indicate that a correspondingsample is a BLA sample. In a case in which a value of pic_type is 4,pic_type may indicate that a corresponding sample is an unconstrained Isample. In this case, the number of bits assigned to the pic_type fieldand/or the dependency_(—) level for the HEVE stream may be reduced. Asample may indicate the same meaning as a picture.

FIG. 15 is a view showing the configuration of an HEVC stream supportingtemporal scalability according to an embodiment of the presentinvention.

In this figure, each quadrilateral box may indicate a picture includedin a stream and T_ID may indicate temporal id.

FIG. 16 is a view showing the configuration of a trick play box forrestricting the maximum X speed to support a trick play in an HEVCstream supporting temporal scalability according to an embodiment of thepresent invention (scenario 2).

This figure shows a method of signaling such that a maximallysupportable X speed is restricted to support a trick play in a HEVCstream having a max_temporal_id of more than 0, i.e. supporting temporalscalability. For example, in a case in which a maximum temporal_id is 2,a maximum of X4 speed may be provided.

According to an embodiment of the present invention, a new box “trikhvc”may be defined. A trikhvc box according to an embodiment of the presentinvention may include a pic_type field, a temporal_sub layer_pic_typefield, a max_temporal_id field, a temporal_id field, a constrainttrick_play_mode field, and/or a next_temporal_id field in a for looprepeated by a value of sample_count.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. The pic_type field may indicate a value of 4 bits.

The temporal_sub_layer_pic_type field may indicate whether acorresponding picture is a Temporal Sub-layer Access (TSA) picture or aStep-wise Temporal Sub-layer Access (STSA) picture. In a case in whichtemporal_sub_layer_pic_type is 1, temporal_sub_layer_pic_type mayindicate that a corresponding picture is a TSA picture. In a case inwhich temporal_sub_layer_pic_type is 2, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an STSA picture. In a case inwhich temporal_sub_layer_pic_type is 3, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an unknown picture. HEVC mayclassify temporal_sub_layer_access_pictures to provide temporalscalability and to adaptively change a frame rate. That is, HEVC maydynamically change a frame rate based on a TSA picture and an STSApicture in a layer not having a temporal_id of 0. There may be adifference between TSA and STSA in terms of how and how much a framerate can be changed. That is, there may be a difference between TSA andSTSA in terms of how many temporal_ids can be skipped at once. Forexample, on the assumption that, in a case in which temporal_id is 0, aframe rate is 15p, in a case in which temporal_id is 1, a frame rate is30p, and, in a case in which temporal_id is 2 (max_temporal_id), a framerate is 60p, TSA may directly access a layer having a temporal_id of 2from a layer having a temporal_id of 0 and, therefore, a broadcastingsystem may directly change a service such that a service having a framerate of 60p is provided while a service having a frame rate of 15p isbeing provided. On the other hand, only stepwise access is possible forSTSA and, therefore, STSA may access a layer having a temporal_id of 1from a layer having a temporal_id of 0 and then access a layer having atemporal_id of 2. In this case, therefore, the broadcasting system maysequentially provide a service having a frame rate of 15p, a servicehaving a frame rate of 30p, and a service having a frame rate of 60p.

The max_temporal_id field may indicate a maximum value of temporal_idincluded in a stream.

The temporal_id field may indicate a value of temporal_id calculatedusing a value of nuh_temporal_id_plus1 of HEVC. A value of thetemporal_id field may indicate a value obtained by subtracting 1 from avalue of nuh_temporal_id_plus1.

The constraint_trick_play_mode field may indicate providable maximum Xspeed information. The present invention may signal a providable maximumX speed through an equation of max_trick_play_mode (providable maximum Xspeed)=2^(max_temporal_id) using a value of max_temporal_id. Forexample, in a case in which a maximum temporal_id is 2, the presentinvention may maximally provide an X4 speed (2^2). According to anembodiment of the present invention, the present invention may provide alimitation that a value less than the value calculated through theabove-described equation is assigned to max_trick_play_mode. Forexample, in a case in which a value of max_trick_play_mode is 1, it mayindicate an X2 speed. In a case in which a value of max_trick_play_modeis 2, it may indicate an X4 speed. In a case in which a value ofmax_trick_play_mode is 3, it may indicate an X8 speed. In a case inwhich a value of max_trick_play_mode is 4, it may indicate an X16 speed.Constraint_trick_play_mode may have the same meaning asmax_trick_play_mode. According to an embodiment of the presentinvention, an X speed higher than max_trick_play_mode may not besupported but an X speed equal to max_trick_play_mode may be supported.In addition, according to an embodiment of the present invention, aconstraint that a value less than a value of max_trick_play_mode isassigned may be signaled.

The next_temporal_id field may indicate a movable temporal_id to informof a maximally changeable frame rate according totemporal_sub_layer_pic_type. For example, when it is necessary to returnto a normal X speed (X1 speed) during provision of an X4 speed trickplay for displaying only pictures having a temporal_id of 0 in a streamhaving a max_temporal_id of 2, next_temporal_id may have a value ofmax_temporal_id in a case in which temporal_sub_layer_pic_type is TSA.On the other hand, next_temporal_id may have a value obtained by adding1 to a value of temporal_id in a case in whichtemporal_sub_layer_pic_type is STSA.

FIG. 17 is a view showing the configuration of a trick play box forrestricting the maximum X speed to support a trick play in an HEVCstream supporting temporal scalability according to another embodimentof the present invention (scenario 2)

This figure shows a method of signaling such that a maximallysupportable X speed is restricted to support a trick play in a HEVCstream having a max_temporal_id of more than 0, i.e. supporting temporalscalability. For example, in a case in which a maximum temporal_id is 2,a maximum of X4 speed may be provided.

According to an embodiment of the present invention, a trick play of anHEVC stream may be executed using a conventionally defined box “trik”.According to an embodiment of the present invention, an AVC or HEVCtrick play may be selected using a flag.

A trik box according to an embodiment of the present invention mayinclude a pic_type field, dependency_level field,temporal_sub_layer_pic_type field, max_temporal_id field, temporal_idfield, constraint_trick_play_mode field, and/or a next_temporal_id fieldin a for loop repeated by a value of flag and sample_count.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. In a case in which a value of flag according to an embodimentof the present invention is 0, the pic_type field may indicate a valueof 2 bits. In a case in which a value of flag is 1, the pie type fieldmay indicate a value of 4 bits.

The dependency_level field may indicate a dependency level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 6 bits.

The temporal_sub_layer_pic_type field may indicate whether acorresponding picture is a Temporal Sub-layer Access (TSA) picture or aStep-wise Temporal Sub-layer Access (STSA) picture. In a case in whichtemporal_sub_layer_pic_type is 1, temporal_sub_layer_pic_type mayindicate that a corresponding picture is a TSA picture. In a case inwhich temporal_sub_layer_pic_type is 2, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an STSA picture. In a case inwhich temporal_sub_layer_pic_type is 3, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an unknown picture. HEVC mayclassify temporal_sub_layer_access_pictures to provide temporalscalability and to adaptively change a frame rate. That is, HEVC maydynamically change a frame rate based on a TSA picture and an STSApicture in a layer not having a temporal_id of 0. There may be adifference between TSA and STSA in terms of how and how much a framerate can be changed. That is, there may be a difference between TSA andSTSA in terms of how many temporal_ids can be skipped at once. Forexample, on the assumption that, in a case in which temporal_id is 0, aframe rate is 15p, in a case in which temporal_id is 1, a frame rate is30p, and, in a case in which temporal_id is 2 (max_temporal_id), a framerate is 60p, TSA may directly access a layer having a temporal_id of 2from a layer having a temporal_id of 0 and, therefore, a broadcastingsystem may directly change a service such that a service having a framerate of 60p is provided while a service having a frame rate of 15p isbeing provided. On the other hand, only stepwise access is possible forSTSA and, therefore, STSA may access a layer having a temporal_id of 1from a layer having a temporal_id of 0 and then access a layer having atemporal_id of 2. In this case, therefore, the broadcasting system maysequentially provide a service having a frame rate of 15p, a servicehaving a frame rate of 30p, and a service having a frame rate of 60p.

The max_temporal_id field may indicate a maximum value of temporal_idincluded in a stream.

The temporal_id field may indicate a value of temporal_id calculatedusing a value of nuh_temporal_id_plus1 of HEVC. A value of thetemporal_id field may indicate a value obtained by subtracting 1 from avalue of nuh_temporal_id_plus1.

The constraint_trick_play_mode field may indicate providable maximum Xspeed information. The present invention may signal a providable maximumX speed through an equation of max_trick_play_mode (providable maximum Xspeed)=2^(max_temporal_id) using a value of max_temporal_id. Forexample, in a case in which a maximum temporal_id is 2, the presentinvention may maximally provide an X4 speed (2^2). According to anembodiment of the present invention, the present invention may provide alimitation that a value less than the value calculated through theabove-described equation is assigned to max_trick_play_mode. Forexample, in a case in which a value of max_trick_play_mode is 1, it mayindicate an X2 speed. In a case in which a value of max_trick_play_modeis 2, it may indicate an X4 speed. In a case in which a value ofmax_trick_play_mode is 3, it may indicate an X8 speed. In a case inwhich a value of max_trick_play_mode is 4, it may indicate an X16 speed.Constraint_trick_play_mode may have the same meaning asmax_trick_play_mode.

The next_temporal_id field may indicate a movable temporal_id to informof a maximally changeable frame rate according totemporal_sub_layer_pic_type. For example, when it is necessary to returnto a normal X speed (X1 speed) during provision of an X4 speed trickplay for displaying only pictures having a temporal_id of 0 in a streamhaving a max_temporal_id of 2, next_temporal_id may have a value ofmax_temporal_id in a case in which temporal_sub_layer_pic_type is TSA.On the other hand, next_temporal_id may have a value obtained by adding1 to a value of temporal_id in a case in whichtemporal_sub_layer_pic_type is STSA.

FIG. 18 is a view showing a frame rate changing method in a case inwhich a temporal sub-layer picture type is TSA according to anembodiment of the present invention.

In a case in which a temporal sub-layer picture type is TSA as shown inthis figure, a receiving side may directly display a stream at an X1speed (normal X speed) during display of only a stream of a layer havinga temporal_id of 0, i.e. during execution of a trick play at an X4speed.

In a case in which a temporal sub-layer picture type is TSA as shown inthis figure, the receiving side may directly decode and display apicture having a temporal_id of 2 during decoding and displaying of apicture having a temporal_id of 0.

FIG. 19 is a view showing a frame rate changing method in a case inwhich a temporal sub-layer picture type is STSA according to anembodiment of the present invention (scenario 3).

In a case in which a temporal sub-layer picture type is STSA as shown inthis figure, a receiving side may not directly display a stream at an X1speed (normal X speed) during display of only a stream of a layer havinga temporal_id of 0, i.e. during execution of a trick play at an X4speed. The receiving side may display a stream at an X2 speed and thendisplay the stream at an X1 speed. In a case in which a temporalsub-layer picture type according to an embodiment of the presentinvention is STSA, therefore, a method of informing of a limitation fora convertible X speed may be needed. That is, it may be necessary tosignal next_temporal_id.

In a case in which a temporal sub-layer picture type is STSA and it isnecessary to display a stream at an X1 speed during displaying of thestream at an X4 speed as shown in this figure, the receiving side maynot directly decode and display a picture having a temporal_id of 2during decoding and displaying of a picture having a temporal_id of 0.The receiving side may decode and display a picture having a temporal_idof 1 and then decode and display a picture having a temporal_id of 2.

FIG. 20 is a view showing the configuration of a trick play box forsupporting a high X speed trick play in an HEVC stream supportingtemporal scalability according to an embodiment of the present invention(scenario 3).

According to an embodiment of the present invention, a new box “trikhvc”may be defined. A trikhvc box according to an embodiment of the presentinvention may include a pic_type field, a temporal_sub_layer_pic_typefield, a max_temporal_id field, a temporal_id field, a next_temporal_idfield, and/or a dependency_level field in a for loop repeated by a valueof sample_count.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. The pie type field may indicate a value of 4 bits.

The temporal_sub_layer_pic_type field may indicate whether acorresponding picture is a Temporal Sub-layer Access (TSA) picture or aStep-wise Temporal Sub-layer Access (STSA) picture. In a case in whichtemporal_sub_layer_pic_type is 1, temporal_sub_layer_pic_type mayindicate that a corresponding picture is a TSA picture. In a case inwhich temporal_sub_layer_pic_type is 2, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an STSA picture. In a case inwhich temporal_sub_layer_pic_type is 3, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an unknown picture. HEVC mayclassify temporal_sub_layer_access_pictures to provide temporalscalability and to adaptively change a frame rate. That is, HEVC maydynamically change a frame rate based on a TSA picture and an STSApicture in a layer not having a temporal_id of 0. There may be adifference between TSA and STSA in terms of how and how much a framerate can be changed. That is, there may be a difference between TSA andSTSA in terms of how many temporal_ids can be skipped at once. Forexample, on the assumption that, in a case in which temporal_id is 0, aframe rate is 15p, in a case in which temporal_id is 1, a frame rate is30p, and, in a case in which temporal_id is 2 (max_temporal_id), a framerate is 60p, TSA may directly access a layer having a temporal_id of 2from a layer having a temporal_id of 0 and, therefore, a broadcastingsystem may directly change a service such that a service having a framerate of 60p is provided while a service having a frame rate of 15p isbeing provided. On the other hand, only stepwise access is possible forSTSA and, therefore, STSA may access a layer having a temporal_id of 1from a layer having a temporal_id of 0 and then access a layer having atemporal_id of 2. In this case, therefore, the broadcasting system maysequentially provide a service having a frame rate of 15p, a servicehaving a frame rate of 30p, and a service having a frame rate of 60p.

The max_temporal_id field may indicate a maximum value of temporal_idincluded in a stream.

The temporal_id field may indicate a value of temporal id calculatedusing a value of nuh_temporal_id_plus1 of HEVC. A value of thetemporal_id field may indicate a value obtained by subtracting 1 from avalue of nuh_temporal_id_plus1.

The next_temporal_id field may indicate a movable temporal_id to informof a maximally changeable frame rate according totemporal_sub_layer_pic_type. For example, when it is necessary to returnto a normal X speed (X1 speed) during provision of an X4 speed trickplay for displaying only pictures having a temporal_id of 0 in a streamhaving a max_temporal_id of 2, next_temporal_id may have a value ofmax_temporal_id in a case in which temporal_sub_layer_pic_type is TSA.On the other hand, next_temporal_id may have a value obtained by adding1 to a value of temporal_id in a case in whichtemporal_sub_layer_pic_type is STSA.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 6 bits.

According to an embodiment of the present invention, the trick play boxshown in this figure may include a max_trick_play_mode field indicatingthe maximum X speed supportable in a trick play.

According to an embodiment of the present invention, in a case in whichmax_temporal_id is 2, the receiving side may decode only pictures havingtemporal_ids of 0 and 1 to provide an X2 speed trick play service. Inaddition, the receiving side may decode and display only pictures havinga temporal_id of 0 to provide an X4 speed trick play service.Furthermore, the receiving side may classify pictures having atemporal_id of 0 according to dependency_level and decode and displayonly pictures having corresponding dependency_level to provide a higherthan X4 speed trick play service.

FIG. 21 is a view showing the configuration of a trick play box forsupporting a high X speed trick play in an HEVC stream supportingtemporal scalability according to another embodiment of the presentinvention.

According to an embodiment of the present invention, a trick play of anHEVC stream may be executed using a conventionally defined box “trik”.According to an embodiment of the present invention, an AVC or HEVCtrick play may be selected using a flag.

A trik box according to an embodiment of the present invention mayinclude a pic_type field, a dependency_level field, atemporal_sub_layer_pic_type field, a max_temporal_id field, atemporal_id field, and/or a next_temporal_id field in a for looprepeated by a value of flag and sample_count.

Sample_count may mean the total number of pictures included in a stream.One sample may mean one picture.

The pic_type field may mean a picture type defined in NAL_unit_type ofHEVC. Some NAL_unit_types which may be used for a trick play may beselected and used as pic_type according to an embodiment of the presentinvention. In a case in which a value of flag according to an embodimentof the present invention is 0, the pic_type field may indicate a valueof 2 bits. In a case in which a value of flag is 1, the pic_type fieldmay indicate a value of 4 bits.

The dependency_level field may indicate a dependency_level of acorresponding picture. Dependency_level according to an embodiment ofthe present invention may be used in a case in which a trick play isexecuted. The dependency_level field may be identical to adependency_level field used in a conventional trick play box of AVC. Forexample, execution of a trick play including samples having adependency_level of 3 may mean decoding and displaying of only sampleshaving a dependency_level of 1, 2, or 3. Consequently, dependency_levelmay mean a level of a layer which may be discarded in executing a trickplay. Even in a case in which a leading picture exists, a decodableleading picture may have a dependency_level and a receiving side maydecode and display only corresponding pictures while skippingnon-corresponding pictures in the same manner as in a conventional trickplay method. The dependency_level field may indicate a value of 6 bits.

The temporal_sub_layer_pic_type field may indicate whether acorresponding picture is a Temporal Sub-layer Access (TSA) picture or aStep-wise Temporal Sub-layer Access (STSA) picture. In a case in whichtemporal_sub_layer_pic_type is 1, temporal_sub_layer pie type mayindicate that a corresponding picture is a TSA picture. In a case inwhich temporal_sub_layer_pic_type is 2, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an STSA picture. In a case inwhich temporal_sub_layer_pic_type is 3, temporal_sub_layer_pic_type mayindicate that a corresponding picture is an unknown picture. HEVC mayclassify temporal_sub_layer_access pictures to provide temporalscalability and to adaptively change a frame rate. That is, HEVC maydynamically change a frame rate based on a TSA picture and an STSApicture in a layer not having a temporal_id of 0. There may be adifference between TSA and STSA in terms of how and how much a framerate can be changed. That is, there may be a difference between TSA andSTSA in terms of how many temporal_ids can be skipped at once. Forexample, on the assumption that, in a case in which temporal_id is 0, aframe rate is 15p, in a case in which temporal_id is 1, a frame rate is30p, and, in a case in which temporal_id is 2 (max_temporal_id), a framerate is 60p, TSA may directly access a layer having a temporal_id of 2from a layer having a temporal_id of 0 and, therefore, a broadcastingsystem may directly change a service such that a service having a framerate of 60p is provided while a service having a frame rate of 15p isbeing provided. On the other hand, only stepwise access is possible forSTSA and, therefore, STSA may access a layer having a temporal_id of 1from a layer having a temporal_id of 0 and then access a layer having atemporal_id of 2. In this case, therefore, the broadcasting system maysequentially provide a service having a frame rate of 15p, a servicehaving a frame rate of 30p, and a service having a frame rate of 60p.

The max_temporal_id field may indicate a maximum value of temporal_idincluded in a stream.

The temporal_id field may indicate a value of temporal_id calculatedusing a value of nuh_temporal_id_plus1 of HEVC. A value of thetemporal_id field may indicate a value obtained by subtracting 1 from avalue of nuh_temporal_id_plus1.

The next_temporal_id field may indicate a movable temporal_id to informof a maximally changeable frame rate according totemporal_sub_layer_pic_type. For example, when it is necessary to returnto a normal X speed (X1 speed) during provision of an X4 speed trickplay for displaying only pictures having a temporal_id of 0 in a streamhaving a max_temporal_id of 2, next_temporal_id may have a value ofmax_temporal_id in a case in which temporal_sub_layer_pic_type is TSA.On the other hand, next_temporal_id may have a value obtained by adding1 to a value of temporal_id in a case in whichtemporal_sub_layer_pic_type is STSA.

According to an embodiment of the present invention, the trick play boxshown in this figure may include a max_trick_play_mode field indicatingthe maximum X speed supportable in a trick play.

According to an embodiment of the present invention, in a case in whichmax_temporal_id is 2, the receiving side may decode only pictures havingtemporal_ids of 0 and 1 to provide an X2 speed trick play service. Inaddition, the receiving side may decode and display only pictures havinga temporal_id of 0 to provide an X4 speed trick play service.Furthermore, the receiving side may classify pictures having atemporal_id of 0 according to dependency_level and decode and displayonly pictures having a corresponding dependency_level to provide ahigher than X4 speed trick play service.

FIG. 22 is a view showing the structure of a broadcast signal receivingsystem according to an embodiment of the present invention.

A broadcast signal receiving system according to an embodiment of thepresent invention may include a player device 22010, a storage device22020, a KIC server 22030, a license server 22040, and/or a downloadserver 22050.

The player device 22010 may include a UHD TV. The player device mayinclude an SCSA application and a traditional file system

The storage device 22020 may include an SD card, a USB memory, and/or anSSD memory. The storage device may include a traditional file system.

The KIC server 22030 may include information for identifying personalinformation.

The license server 22040 may include information related to a license ofcontent.

The download server 22050 may include content and information related tothe content.

According to an embodiment of the present invention, the player devicemay perform the following procedures to acquire a license of content.First, the player device may confirm whether the storage device includesa license file and, in a case in which the storage device includes thelicense file, may acquire a content key from the license file. In a casein which the storage device does not include the license file, theplayer device may confirm bulk content and, in a case in which the bulkcontent includes a license file, may acquire a content key from thelicense file. The player device may acquire a license from the licenseserver using the content key.

According to an embodiment of the present invention, in order to displaydownloaded content, it may be necessary for a receiver to acquire alicense of the corresponding content.

FIG. 23 is a view showing the structure of a receiving end according toan embodiment of the present invention.

A receiving end according to an embodiment of the present invention mayinclude a UHD display unit 23010, a second device 23020, a UHD decodingunit 23030, a USB memory 23040, and/or a remote controller 23050.

The UHD display unit 23010 may include the UHD decoding unit 23030 andmay indicate a UHD TV.

The second device 23020 may indicate a mobile phone, a tablet PC, or alaptop computer.

The UHD decoding unit 23030 may include the UHD display unit 23010 andmay indicate a UHD TV.

The USB memory 23040 ma indicate another memory device. A USB memoryaccording to an embodiment of the present invention may store metadata,a URL, and/or a presentation list for a second screen.

The remote controller 23050 may indicate a controller suitable for a UHDTV.

According to an embodiment of the present invention, the UHD TV maytransmit content metadata included in the USB memory to the seconddevice and display the content metadata on a display unit of the seconddevice. First, a user may store metadata, a URL, and/or a presentationlist which will be displayed on the second screen in the USB memory. TheUHD TV and the second device may automatically pair with each other. Atthis time, both the devices may be connected to each other throughUPnP-based SSDP. When the USB memory is connected to the UHD TV, the UHDTV may transmit content information which will be displayed on thesecond screen, i.e. information included in the USB memory, to thesecond device. The second device may display information received fromthe UHD TV.

According to an embodiment of the present invention, the user may storeinformation regarding a trick play in the USB memory and the informationregarding the trick play may be displayed through the second deviceconnected to the UHD TV.

FIG. 24 is a view showing a trick play method compositively using atemporal id and a tier according to an embodiment of the presentinvention.

According to an embodiment of the present invention, a tier value may beassigned to only a picture having a temporal id of 0.

As shown in this figure, a receiver according to an embodiment of thepresent invention may decode and display pictures having a temporal idof 0, 1, 2, or 3 to execute a normal X speed trick play, may decode anddisplay pictures having a temporal id of 0, 1, or 2 to execute an X2speed trick play, may decode and display pictures having a temporal idof 0 or 1 to execute an X4 speed trick play, and may decode and displaypictures having a temporal id of 0 to execute an X8 speed trick play.The present invention may assign different tier values to pictureshaving a temporal id of 0 to execute a higher than X8 speed trick play.

According to an embodiment of the present invention, the followingmethods may be used to provide a trick play. A trick play may beprovided by mapping a tier and a temporal id to use a PVR_assist_infodescriptor (scenario A). A trick play may be provided by including atrick play using a temporal id in a PVR_assist_info descriptor (scenarioB). A trick play may be provided by parsing nuh_temporal_id_plus1information of NAL_unit_header and selecting only packets necessary fora real trick play (scenario C).

A temporal sub-layer or a temporal id according to an embodiment of thepresent invention is a term introduced to support temporal scalabilityin HEVC and may be signaled by nuh_temporal_id_plus1 of NAL_unit_header.

A tier according to an embodiment of the present invention is a termintroduced to support a trick play in an AVC stream or an mpeg-2 streamand may be included in an adaptation field in a TS packet.

FIG. 25 is a view showing a trick play method based on a conventionaltier concept according to an embodiment of the present invention.

A conventional tier according to an embodiment of the present inventionmay indicate dependency between layers.

As shown in this figure, pictures having a temporal_id of 3 may have atier value of 6, pictures having a temporal id of 2 may have a tiervalue of 4, and pictures having a temporal id of 1 may have a tier valueof 3. In addition, I pictures having a temporal id of 0 may have a tiervalue of 1 and I pictures having a temporal id of 0 may have a tiervalue of 2. That is, pictures having a temporal id of 0 may have thesame temporal and different tier values.

According to an embodiment of the present invention, pictures havingmax_temporal_id, i.e. highest dependency_level, may have a tier value of6 or 7. Pictures having other temporal_ids may have a tier value of 1 to5. At this time, pictures corresponding to a layer having a temporal_idof 0 may have a tier value of 1 or 2 according to a picture type.

FIG. 26 is a view showing a trick play method based on a method ofmapping one temporal id to one tier one to one according to anembodiment of the present invention (scenario A-a).

According to an embodiment of the present invention, a method of mappinga temporal id and a tier may be used to provide a trick play based on anHEVC stream which includes a temporal id but does not include tierinformation (scenario A).

In order to provide a trick play according to an embodiment of thepresent invention, a method of mapping one temporal id to one tier oneto one may be used (scenario A-a) and a method of mapping one temporalid to several tiers may be used (scenario A-b).

According to an embodiment of the present invention, in scenario A-a andscenario A-b as described above, a value of temporal id may be mapped toa tier one to one as it is irrespective of the meaning of a conventionaltier.

According to another embodiment of the present invention, in scenarioA-a and scenario A-b as described above, a value of temporal id may bemapped to a tier one to one and a maximum temporal id may be mapped totier 6 or 7, which has meaning of a conventional tier as a discardablepicture as it is.

According to scenario A as described above, most of a conventionalPVR_assist_info descriptor may be used as it is. However, an embodimentof the present invention is based on a HEVC stream and, therefore, it isnecessary to modify some fields included in the PVR_assist_infodescriptor. For example, it may be newly defined that aPVR_assist_tier_m_cumulative_frames field included in thePVR_assist_info descriptor may deliver a value of the minimum number offrames extractable per 1.28 seconds from tier 1 through aPVR_assist_tier_m field (This field conveys the value of the intendedminimum number of extractable frames per 1.28 sec. from tier 1 through“PVR_assist_teir_m”).

This figure shows a trick play method based on scenario A-a according toan embodiment of the present invention.

As shown in this figure, pictures having a temporal_id of 3 may bemapped to tier 4, pictures having a temporal id of 2 may be mapped totier 3, pictures having a temporal id of 1 may be mapped to tier 2, andpictures having a temporal id of 0 may be mapped to tier 1.

Scenario A according to an embodiment of the present invention may notprovide an 8× and higher speed trick play.

FIG. 27 is a view showing a trick play method based on a method ofmapping one temporal_id to one tier one to one according to anotherembodiment of the present invention (scenario A-a).

According to an embodiment of the present invention, a value of temporalid may be mapped to a tier one to one and a maximum temporal_id may bemapped to tier 6 or 7, which has meaning of a conventional tier as adiscardable picture as it is unlike the previous figure.

As shown in this figure, pictures having a temporal id of 3 may bemapped to tier 6, pictures having a temporal id of 2 may be mapped totier 3, pictures having a temporal id of 1 may be mapped to tier 2, andpictures having a temporal id of 0 may be mapped to tier 1.

This figure is different from the previous figure in that picturescorresponding to temporal id 3, which is a maximum temporal id, aremapped to tier 6.

FIG. 28 is a view showing a result of mapping one temporal id to onetier one to one according to an embodiment of the present invention.

This figure shows a result of mapping a value of temporal id to a tierone to one as it is irrespective of the meaning of a conventional tierin scenario A-a according to an embodiment of the present invention.

A nuh_temporal_id_plus1 field shown in this figure may be a fieldincluded in NAL_unit_header and may indicate a value obtained by adding1 to a temporal id. For example, in a case in which a value of thenuh_temporal_id_plus1 field is 1, a temporal id may be 0. As shown inthis figure, therefore, pictures having a temporal id of 0 may be mappedto tier 1, pictures having a temporal id of 1 may be mapped to tier 2,pictures having a temporal id of 2 may be mapped to tier 3, and pictureshaving a temporal id of 3 may be mapped to tier 4.

According to an embodiment of the present invention, a new tier mappedwith a temporal id may be different in meaning from a conventionallyused tier. Conventional tiers 6 and 7 may mean discardable pictures andtier 7 may mean a picture which is not used as reference. However, atier newly defined through mapping may not have meaning of conventionaltiers 6 and 7.

An embodiment of the present invention may map a temporal sub-layer anda tier so as to have the same number and may use the above-describedmapping information when executing a trick play.

FIG. 29 is a view showing a result of mapping one temporal id to onetier one to one according to another embodiment of the presentinvention.

This figure shows a result of mapping a value of temporal id to a tierone to one and mapping a maximum temporal id to tier 6 or 7, which hasmeaning of a conventional tier as a discardable picture as it is inscenario A-a according to another embodiment of the present invention.

A nuh_temporal_id plus1 field shown in this figure may be a fieldincluded in NAL_unit_header and may indicate a value obtained by adding1 to a temporal id. For example, in a case in which a value of thenuh_temporal_id_plus1 field is 1, a temporal id may be 0. As shown inthis figure, therefore, pictures having a temporal_id of 0 may be mappedto tier 1, pictures having a temporal id of 1 may be mapped to tier 2,pictures having a temporal id of 2 may be mapped to tier 3, and pictureshaving a temporal id of 3 may be mapped to tier 6.

According to an embodiment of the present invention, a new tier mappedwith a temporal id may be identical in meaning to a conventionally usedtier. Tiers 6 and 7 may mean discardable pictures, tier 6 may mean apicture which is used as reference, and tier 7 may mean a picture whichis not used as reference. As described above, therefore, pictures havinga nuh_temporal_id plus1 of 4 may be mapped to tier 6. Pictures which arenot used as reference may be mapped to tier 7.

FIG. 30 is a view showing a trick play method based on a method ofmapping one temporal id to several tiers according to an embodiment ofthe present invention (scenario A-b).

As shown in this figure, pictures having a temporal id of 1, which is amaximum temporal id, may be mapped to tier 4 or 6 and the other fivepictures having a temporal id of 0 may be mapped to tiers 0 to 3.

According to an embodiment of the present invention, a new tier mappedwith a temporal id may be different in meaning from a conventionallyused tier. Conventional tiers 6 and 7 may mean discardable pictures andtier 7 may mean a picture which is not used as reference. However, atier newly defined through mapping may not have meaning of conventionaltiers 6 and 7. As shown in this figure, therefore, pictures having atemporal id of 1 may be mapped to tier 4 (30010).

According to another embodiment of the present invention, a new tiermapped with a temporal id may be identical in meaning to aconventionally used tier. Tiers 6 and 7 may mean discardable pictures,tier 6 may mean a picture which is used as reference, and tier 7 maymean a picture which is not used as reference. As shown in this figure,therefore, pictures having a temporal id of 1 may be mapped to tier 6(30020).

FIG. 31 is a view showing the configuration of an adaptation field of aTS packet including information for mapping of a temporal id and a tieraccording to an embodiment of the present invention.

An embodiment of the present invention may provide a descriptor forvalues of tier and nuh_temporal_id_plus1 with speed information for atrick play.

According to an embodiment of the present invention, information for aconventional trick play is included in an adaptation field of a TSpacket and, therefore, HEVC_temporal_id_tier_mapping_info, which isinformation for a trick play of a HEVC stream including a temporal_id,may also be included in the above-described adaptation field.

This figure shows the configuration of a data field included in theadaptation field of the TS packet.

As shown in this figure, in a case in which data_field_tag is 0x00, acorresponding data field may indicate a reserved field. In a case inwhich data_field_tag is 0x01, a corresponding data field may indicate anannouncement switching data field. In a case in which data_field_tag is0x02, a corresponding data field may indicate a data field forAU_information. In a case in which data_field_tag is 0x03, acorresponding data field may indicate a data field forPVR_assist_information. In a case in which data_field_tag is 0x04, acorresponding data field may indicate a data field indicating a TSAPtime line. In a case in which data_field_tag is 0x05, a correspondingdata field may indicate a data field forHEVC_temporal_id_tier_mapping_info.

An embodiment of the present invention may map a tier value to atemporal_id using an HEVC_temporal_id_tier_mapping_info descriptor andprovide a tier-based trick play using a PVR_assist_informationdescriptor.

FIG. 32 is a view showing the configuration of HEVC_temporal_(—) id_(—)mapping_info according to an embodiment of the present invention.

HEVC_temporal_id_tier_mapping_info according to an embodiment of thepresent invention may include an included_temporal_id_flag field, atemporal_sub_layer_dependency_flag field, a max_temporal_id_plus1 field,a temporal_id_plus1 field, a curr_tier_num field, and/or atrick_play_speed field.

The included_temporal_id_flag field may signal whether encoding has beenperformed using a temporal_id.

The temporal_sub_layer_dependency_flag field may indicate dependencybetween temporal sub-layers. That is, thetemporal_sub_layer_dependency_flag field has a value of 1 in a case inwhich a lower temporal sub-layer picture does not refer to an uppertemporal sub-layer picture.

The max_temporal_id_plus1 field may indicate a maximum value of atemporal id. A value indicated by the max_temporal_id_plus1 field is avalue obtained by adding 1 to a temporal_id.

The temporal_id_plus1 field may have a value equal to a value indicatedby nuh_temporal_id_plus1 included in an NAL unit header.

The curr_tier_num field may indicate a tier value mapped withtemporal_id_plus1.

The trick_play_speed field may indicate a trick play speed that can bemaximally provided according to a value of a temporal id.

An if(max_temporal_id_plus1>1) condition statement may indicate a casein which max_temporal_id_plus1 is greater than 1, i.e. a stream usingtemporal scalability. In this case, a trick play may be provided using atemporal_id and, therefore, an embodiment of the present invention maymap a temporal_id to a tier so as to use conventionalPVR_assist_information.

Another embodiment of the present invention may locate thetemporal_id_plus1 field in a for loop at the same level as thecurr_tier_num field and the trick_play_speed and signal a tier numberbased on each temporal id and a speed for a trick play. An embodiment ofthe present invention may create a look up table using a descriptorincluding the above-described HEVC_temporal_id_tier_mapping_info and mayinterpret and use tier-related information of PVR_assist_information astemporal_id using the above-described look up table.

Another embodiment of the present invention may delete a for loop fromthe above-described HEVC_temporal_id_tier_mapping_info and locate thecurr_tier_num field and the trick_play_speed at a level at which thetemporal_id_plus1 field is located. An embodiment of the presentinvention may signal a descriptor including the above-describedHEVC_temporal_id_tier_mapping_info per picture.

FIG. 33 is a view showing the configuration of a trick play_speed fieldincluded in HEVC_temporal_id_tier_mapping_info according to anembodiment of the present invention.

In a case in which a trick_play_speed field according to an embodimentof the present invention is 0, a providable X speed of a trick play maybe an X1 speed. In a case in which a trick_play_speed field is 1, aprovidable X speed of a trick play may be an X2 speed. In a case inwhich a trick_play_speed field is 2, a providable X speed of a trickplay may be an X4 speed. In a case in which a trick play_speed field is3, a providable X speed of a trick play may be an X8 speed. In a case inwhich a trick_play_speed field is 4, a providable X speed of a trickplay may be an X16 speed. In a case in which a trick_play_speed field is5, a providable X speed of a trick play may be an X32 speed. In a casein which a trick_play_speed field is 6, a providable X speed of a trickplay may be an X64 speed.

FIG. 34 is a view showing the configuration of PVR_assist_informationaccording to an embodiment of the present invention.

PVR_assist_information according to an embodiment of the presentinvention may include a data_field_tag field, a data_field_length field,a PVR_assist_tier_pic_num field, aPVR_assist_block_trick_mode_present_flag field, aPVR_assist_pic_struct_present_flag field, aPVR_assist_tier_next_pic_in_tier_present_flag field, aPVR_assist_substream_info_present_flag field, aPVR_assist_extension_present_flag field, aPVR_assist_segmentation_info_present_flag field, aPVR_assist_tier_m_cumulative_frames_present_flag field, aPVR_assist_tier_n_mmco_present_flag field, a PVR_assist_reserved_0field, a PVR_assist_seg_id field, a PVR_assist_prg_id field, aPVR_assist_seg_start_flag field, a PVR_assist_seg_end_flag field, aPVR_assist_prg_start_flag field, a PVR_assist_prg_stop_flag field, aPVR_assist_scene_change_flag field, a PVR_assist_tier_m field, aPVR_assist_tier_m_cumulative_frames field, and/or aPVR_assist_tier_n_mmco field.

The data_field_tag field may indicate that a corresponding data field isPVR_assist_information. The data_field_tag field may have a value of0x03.

The data_field_length field may indicate a length ofPVR_assist—_information excluding the data_field_tag field and thedata_field_length field.

The PVR_assist_tier_pic_num field may indicate a tier number of apicture related to PVR_assist_information. A minimum tier number may be0 and a maximum tier number may be 7. Tier number 0 may be reserved forfuture use. According to an embodiment of the present invention, forHEVC, a tier number of a HEVC RAP picture may be 0 and a tier number ofall other pictures different from the HEVC RAP may be a value obtainedby adding 1 to a temporal id. According to an embodiment of the presentinvention, this field may indicate a tier number of a picture includedin a video stream and may be named tier number information. The tiernumber may be used to signal a temporal sub-layer.PVR_assist_tier_pic_num may be named tier number information.

The PVR_assist_block_trick_mode_present_flag field may have a value of 1at a picture which is not a RAP picture in a case in which this fieldhas a value of 1 at the previous RAP picture.

The PVR_assist_pic_struct_present_flag field may have a value of 1 in acase in which a video stream is an AVC or HEVC stream and aPVR_assist_pict_struct field exists.

The PVR_assist_tier_next_pic_in_tier_present_flag field may have a valueof 1 in a case in which a PVR_assist_tier_next_pic_in_tier field exists.

The PVR_assist_substream_info_present_flag may have a value of 1 in acase in which a PVR_assist_substream_info field exists.

The PVR_assist_extension_present_flag field may have a value of 1 in acase in which any one selected from among thePVR_assist_segmentation_info_present_flag field, thePVR_assist_tier_m_cumulative_frames_present_flag field, thePVR_assist_tier_n_mmco_present_flag field, and aPVR_assist_temporal_id_info_present_flag field has a value of 1.

The PVR_assist_segmentation_info_present_flag field may have a value of1 in a case in which a PVR_assist_segmentation_info field exists. Thisfield may be named segmentation info flag information and may indicateexistence or nonexistence of information regarding a segment to which apicture belongs.

The PVR_assist_tier_m_cumulative_frames_present_flag field may have avalue of 1 in a case in which the PVR_assist_tier_m field and thePVR_assist_tier_m_cumulative_frames field exist. For HEVC, it may berecommended that this field has a value of 0.

The PVR_assist_tier_n_mmco_present_flag field may have a value of 1 in acase in which the PVR_assist_tier_n_mmco field exists. For HEVC, thisfield may have a value of 0.

The PVR_assist_seg_id field may deliver an id of a segment to which apicture belongs. This field may be named segment identifier informationand may indicate an id of a segment to which a picture belongs.

The PVR_assist_prg_id field may deliver an id of a program to which apicture belongs. This field may be named program identifier informationand may indicate an id of a program to which a picture belongs.

The PVR_assist_seg_start_flag field may have a value of 1 in a case of apicture having a first presentation order in one segment. This field maybe named segment start flag information and may identify a picturehaving a first presentation order in each segment.

The PVR_assist_seg_end_flag field may have a value of 1 in a case of apicture having a last presentation order in one segment. This field maybe named segment end flag information and may identify a picture havinga last presentation order in each segment.

The PVR_assist_prg_start_flag field may have a value of 1 in a case of apicture having a first presentation order in one program. This field maybe named program start flag information and may identify a picturehaving a first presentation order in each program.

The PVR_assist_prg_stop_flag field may have a value of 1 in a case of apicture having a last presentation order in one program. This field maybe named program end flag information and may identify a picture havinga last presentation order in each program.

The PVR_assist_scene_change_flag field may have a value of 1 in a caseof a first picture of a new scene in presentation order.

The PVR_assist_tier_m field may indicate a tier number related to thePVR_assist_tier_m_cumulative_frames field. For HEVC, this field may notexist.

The PVR_assist_tier_m_cumulative_frames field may deliver a value of theminimum number of frames extractable per second from tier 1 through thePVR_assist_tier_m field.

The PVR_assist_tier_n_mmco field may indicate a minimum tier numberbelow MMCOs which may be ignored by a decoder during execution of atrick play. For HEVC, this field may not exist.

PVR_assist_information according to an embodiment of the presentinvention may further include a PVR_assist_tier_next_pic_tier field. ThePVR_assist_tier_next_pic_tier may indicate a relative position of thenext picture in decoding order among pictures having a tier number equalto a value indicated by the PVR_assist_tier_pic_num field and may benamed tier next picture information.

PVR_assist_information according to an embodiment of the presentinvention may include metadata for executing a trick play of video dataand may be named PVR assist information.

FIG. 35 is a view showing the configuration of PVR_assist_informationhaving a temporal id frame work added thereto according to an embodimentof the present invention (scenario B-a-a).

An embodiment of the present invention may provide a method of includinga trick play using a temporal id in conventional PVR_assist_informationincluded in an adaptation field of a TS packet. That is, an embodimentof the present invention may provide a temporal id frame work.

An embodiment of the present invention may signalPVR_assist_temporal_id_plus1 together with conventionalPVR_assist_tier_pic_num to support temporal scalability based on atemporal id.

According to an embodiment of the present invention,PVR_assist_information may include all fields described above withreference to the previous figure showing the configuration ofPVR_assist_information, a PVR_assist_temporal_id_plus1 field,PVR_assist_temporal_id_info_present_flag field, and/or aPVR_assist_max_temporal_id_plus1 field.

In this figure, fields having the same names as the fields describedabove with reference to the previous figure showing the configuration ofPVR_assist_information may have the same meanings as the fieldsdescribed above with reference to the previous figure.

The PVR_assist_temporal_id_plus1 field may indicate a value of atemporal id of a current frame and may actually indicate a value equalto a value of nuh_temporal_id_plus1 included in an NAL unit header.

The PVR_assist_temporal_id_info_present_flag field may include whetherinformation related to a temporal id is included. In a case in which thePVR_assist_max_temporal_id_plus1 field exists, this field may indicate avalue of 1. This field may be provided for every RAP picture.

The PVR_assist_max_temporal_id_plus1 field may indicate a maximum valueof a temporal id and may actually indicate a value obtained by adding 1to the maximum value of the temporal id. This field may have a value ofany one selected from among 0 to 6. This field may be used to provideinformation regarding speed of a trick play.

According to an embodiment of the present invention, an X speed of atrick play may be calculated using a value of thePVR_assist_max_temporal_id_plus1 field and a value of thePVR_assist_temporal_id_plus1 field.

FIG. 36 is a view showing the configuration of PVR_assist_informationhaving a temporal id frame work added thereto according to anotherembodiment of the present invention (scenario B-a-b).

An embodiment of the present invention may provide a method of includinga trick play using a temporal id in conventional PVR_assist_informationincluded in an adaptation field of a TS packet. That is, an embodimentof the present invention may provide a temporal id frame work.

An embodiment of the present invention may use a PVR_assist_tier_pic_numfield as it is and may contain meaning of PVR_assist_temporal_id_plus1in the PVR_assist_tier_pic_num field. In addition, an embodiment of thepresent invention may inform that meaning of a tier has been changedusing a PVR_assist_tier_pic_num_to_temporal_id_flag field.

According to an embodiment of the present invention,PVR_assist_information may include all fields described above withreference to the previous figure showing the configuration ofPVR_assist_information, a PVR_assist_tier_pic_num_to_temporal_id_flagfield, a PVR_assist_temporal_id_info_present_flag field, and/or aPVR_assist_max_temporal_id_plus1 field.

In this figure, fields having the same names as the fields describedabove with reference to the previous figure showing the configuration ofPVR_assist_information may have the same meanings as the fieldsdescribed above with reference to the previous figure. However, thePVR_assist_tier_pic_num field may be used for the temporal id frame workas it is according to an embodiment of the present invention. That is,the PVR_assist_tier_pic_num field may indicate a value of a temporal idof a current frame and may actually have a value equal to a value ofnuh_temporal_id_plus1 included in an NAL unit header.

The PVR_assist_tier_pic_num_to_temporal_id_flag field may have a valueof 1 in a case in which the PVR_assist_tier_pic_num is used as a fieldindicating a temporal id.

The PVR_assist_temporal_id_info_present_flag field may indicate whetherinformation related to a temporal id is included.

The PVR_assist_max_temporal_id_plus1 field may indicate a maximum valueof a temporal id and may actually indicate a value obtained by adding 1to the maximum value of the temporal id.

According to an embodiment of the present invention, an X speed of atrick play may be calculated using a value of thePVR_assist_tier_pic_num having meaning of thePVR_assist_max_temporal_id_plus1 field and thePVR_assist_temporal_id_plus1 field.

Another embodiment of the present invention may include aPVR_assist_framework field having a value of 2 bits or more inPVR_assist_information to classify types of frameworks providing PVR. Anembodiment of the present invention may classify a conventional tier, asubstream framework, and a temporal id framework. In this case, flagvalues included in conventional PVR_assist_information may not be usedand an embodiment of the present invention may configure a conditionstatement on behalf of a tag value corresponding to each framework.

FIG. 37 is a view showing the configuration of PVR_assist_informationfor supporting a trick play using a temporal id according to anembodiment of the present invention (scenario B-b).

PVR_assist_information according to an embodiment of the presentinvention may include a data_field_tag field, a data_field_length field,a PVR_assist_temporal_id_plus1 field, aPVR_assist_substream_info_present_flag field, aPVR_assist_extension_present_flag field, aPVR_assist_temporal_id_present_flag field, aPVR_assist_temporal_sub_layer_dependency_flag field, aPVR_assist_max_temporal_id_plus1 field, a PVR_assist_curr_tier_numfield, and/or a PVR_assist_trick_play_speed field.

The data_field_tag field may indicate that a corresponding data field isPVR_assist_information. The data_field_tag field may have a value of0x03.

The data_field_length field may indicate a length ofPVR_assist_information excluding the data_field_tag field and thedata_field_length field.

The PVR_assist_temporal_id_plus1 field may indicate a value of atemporal id of a current frame and may actually indicate a value equalto a value of nuh_temporal_id_plus1 included in an NAL unit header.

The PVR_assist_substream_info_present_flag field may have a value of 1in a case in which a PVR_assist_substream_info field exists.

The PVR_assist_extension_present_flag field may have a value of 1 in acase in which any one selected from among aPVR_assist_segmentation_info_present_flag field, a PVR_(—)assist_tier_m_cumulative_frames_present_flag field, and aPVR_assist_tier_n_mmco_present_flag field has a value of 1.

The PVR_assist_temporal_id_info_present_flag field may indicate whetherinformation related to a temporal id is included.

The PVR_assist_temporal_sub_layer_dependency_flag field may indicatedependency between temporal sub-layers. That is, thetemporal_sub_layer_dependency_flag field has a value of 1 in a case inwhich a lower temporal sub-layer picture does not refer to an uppertemporal sub-layer picture.

The PVR_assist_max_temporal_id_plus1 field may indicate a maximum valueof a temporal id and may actually indicate a value obtained by adding 1to the maximum value of the temporal id.

The PVR_assist_curr_tier_num field may indicate a tier valuecorresponding to temporal_id_plus1.

The trick_play_speed field may indicate a trick play speed that can bemaximally provided according to a value of a temporal id.

An if(PVR_assist_max_temporal_id_plus1>1) condition statement mayindicate a case in which PVR_assist_max_temporal_id_plus1 is greaterthan 1, i.e. a stream using temporal scalability. In this case, a trickplay may be provided using a temporal_id.

Another embodiment of the present invention may locate thePVR_assist_temporal_id_plus1 field in a for loop at the same level asthe PVR_assist_curr_tier_num field and the PVR_assist_trick_play_speedfield and signal a tier number based on each temporal id and a speed fora trick play.

Another embodiment of the present invention may change and use a valueof the PVR_assist_tier_pic_num field so as to indicate a value of thePVR_assist_temporal_id_plus1 field in a state in which theabove-described field is left as it is. In this case, it is necessary tosignal that meaning of the PVR_assist_tier_pic_num field has beenchanged using the PVR_assist_tier_pic_num_to_temporal_id_flag field.

A further embodiment of the present invention may provide a trick playusing only a temporal id without a tier. That is, a trick play may beprovided by parsing nuh_temporal_id_plus1 information of NAL_unit_headerand selecting only packets necessary for a real trick play (scenario C).For example, in a case in which it is necessary to play a stream havinga temporal id of 0 to 3 at an X2 speed, an embodiment of the presentinvention may provide an X2 speed trick play by delivering only a TSpacket having a nuh_temporal_id_plus1 value of 1, 2, or 3 to a systemdecoder.

FIG. 38 is a view showing a receiving apparatus according to anembodiment of the present invention.

A receiving apparatus according to an embodiment of the presentinvention may include a tuner 38010, a demodulator 38020, a trick playexecution unit 38030, a system decoder and demux 38040, and/or a videodecoder 38050.

The tuner 38010 may receive a broadcast signal transmitted through abroadcasting network, a cable network, and/or an Internet network. Thetuner may receive a transport stream (TS). The TS may include PVR assistinformation for executing a trick play. The PVR assist information mayinclude tier number information and/or maximum temporal identificationinformation. The above-described tier number information may indicate atier number having a value obtained by adding 1 to a temporalidentification information value of a picture different from a RAPpicture and the above-described maximum temporal identificationinformation may indicate a maximum temporal identification informationvalue of a video stream including encoded video data.

The demodulator 38020 may demodulate a broadcast signal modulatedaccording to a modulation method.

The trick play execution unit 38030 may select a TS packet for a trickplay according to a method based on scenarios. Scenarios 1, 2, and 3according to an embodiment of the present invention have been previouslydescribed in detail.

The system decoder and demux 38040 may decode system information andseparate a multiplexed broadcast signal per unit stream. The demux maydemultiplex a received broadcast signal to extract a video stream. Ademux according to an embodiment of the present invention may include afirst extraction unit and/or a second extraction unit according to anembodiment of the present invention. The first extraction unit mayextract a packetized elementary stream (PES) from the received TS. Thesecond extraction unit may extract a video elementary stream (ES) fromthe extracted PES.

The video decoder 38050 may decode a video stream. The video decoder mayinclude the system decoder and the trick play execution unit. The videodecoder may execute a trick play of a video stream by decoding a videostream selected for a trick play based on the PVR assist information.The video decoder may execute a trick play based on the temporalidentification information and the maximum temporal identificationinformation included in the PVR assist information.

A video stream according to an embodiment of the present invention mayindicate a video elementary stream (ES).

FIG. 39 is a view showing comparison between a tier framework and anHEVC temporal sub-layer according to an embodiment of the presentinvention.

A hierarchical structure of an HEVC temporal sub-layer according to anembodiment of the present invention is similar to a tier systemframework. A temporal id according to an embodiment of the presentinvention may be matched to a tier number. An HEVC temporal sub-layeraccording to an embodiment of the present invention may support PVRusing a method similar to the tier system framework.

An HEVC compliant encoder/decoder according to an embodiment of thepresent invention may support an HEVC temporal sub-layer. An temporal idaccording to an embodiment of the present invention may exist in astream encoded by HEVC. In a case in which a stream is encoded by atemporal sub-layer structure, any special encoding structure for a trickplay may not be needed. Consequently, an HEVC temporal sub-layeraccording to an embodiment of the present invention may reduce anencoding burden in a case in which a trick play is supported.

As shown in this figure, in a tier framework, tier 7 meansnon-referenced discardable pictures and tier 6 means referenceddiscardable pictures. However, an HEVC temporal sub-layer according toan embodiment of the present invention may not classify referencedpictures and non-referenced pictures. In the tier framework, tier 1indicates RAP pictures and tier 2 indicates P pictures. In an HEVCtemporal sub-layer according to an embodiment of the present invention,however, temporal id 0 may indicate all of I pictures including IRAPpictures, P pictures, and B pictures.

According to an embodiment of the present invention, other sub-layersmay be designated to temporal ids 6 and 7. As compared with tier numbers6 and 7, therefore, an additional X speed may be supported in a case inwhich a temporal id is used according to an embodiment of the presentinvention.

According to an embodiment of the present invention, it may be necessaryto classify frames in a base sub-layer having a temporal id of 0 so asto support a higher X speed.

FIG. 40 is a view showing the configuration of PVR_assist_informationaccording to another embodiment of the present invention.

According to an embodiment of the present invention, a temporal id givento a video level may be signaled at a system level to filter accessunits (AUs) before a decoding procedure.

According to an embodiment of the present invention, an intra frame maybe signaled in a base sub-layer having a temporal id of 0 so as tosupport a higher X speed

PVR_assist_information according to an embodiment of the presentinvention may include a data_field_tag field, a data_field_length field,a PVR_assist_temporal_id_plus1 field, aPVR_assist_temporal_id_info_present_flag field, aPVR_assist_intra_picture_flag field, a PVR_assist_max_temporal_id_plus1field, a PVR_assist_PB_numbers_in_temporal_id_zero field, aPVR_assist_reserved_0 field, and/or a PVR_assist_reserved_byte field.

The data_field_tag field may indicate that a corresponding data field isPVR_assist_information. The data_field_tag field may have a value of0x03.

The data_field_length field may indicate a length ofPVR_assist_information excluding the data_field_tag field and thedata_field_length field.

The PVR_assist_temporal_id_plus1 field may indicate a temporal id of apicture. Actually, a temporal id may have a value obtained bysubtracting 1 from a value of this field. This field may have a minimumvalue of 1 and a maximum value of 7. For a HEVC stream, this field mayhave a value equal to a value of nuh_temporal_id_plus1.

The PVR_assist_temporal_id_info_present_flag field may have a value of 1in a case in which the PVR_assist_max_temporal_id_plus1 field exists.This field may be provided in only pictures corresponding to RAPpictures.

The PVR_assist_intra_picture_flag field may have a value of 1 in a casein which a current access unit is an intra picture.

The PVR_assist_max_temporal_id_plus1 field may indicate a maximumtemporal id. Actually, the maximum temporal id may indicate a valueobtained by subtracting 1 from a value of this field. This field mayhave a value of 1 to 7.

The PVR_assist_PB_numbers_in_temporalId_zero field may indicate thenumber of frames, existing between intra frames, different from theintra frames in a base sub-layer having a temporal id of 0. This fieldmay be used to estimate speed of a trick play.

The PVR_assist_reserved_0 field is a field reserved for future use.

The PVR_assist_reserved_byte field may indicate a field reserved forfuture use.

FIG. 41 is a view showing a trick play method using an HEVC temporalsub-layer according to an embodiment of the present invention.

A first figure part 41010 of this figure shows that picturescorresponding to one GOP are arranged in presentation order. In thefirst figure part, I may indicate I pictures, B may indicate B pictures,and P may indicate P pictures. In addition, numerical subscripts of thealphabet indicating picture types may indicate presentation order. Inthe first figure part, arrows may indicate reference relationship amongpictures.

A second figure part 41020 of this figure shows a method of providing atrick play using an HEVC temporal sub-layer according to an embodimentof the present invention. One quadrilateral box may indicate onepicture. A number in each quadrilateral box may indicate a temporal id.Symbol x shown in each quadrilateral box may indicate a picture decodedand presented during execution of a trick play. As shown in the secondfigure part, X2 to X8 speed trick plays may be provided by the HEVCtemporal sub-layer.

A third figure part 41030 of this figure shows a method of providing atrick play using base sub-layer signaling according to an embodiment ofthe present invention. An embodiment of the present invention may decodeand present only intra pictures to provide X12, X24, and X48 speed trickplays.

FIG. 42 is a view showing a broadcast signal transmitting methodaccording to an embodiment of the present invention.

An embodiment of the present invention may transmit a broadcast signalthrough the following procedures. First, an embodiment of the presentinvention may encode video data to create a video elementary stream (ES)(S42010). The video elementary stream (ES) may be encoded by an AVC orHEVC codec. Next, an embodiment of the present invention may create apacketized elementary stream (PES) including the video elementary stream(ES) (S42020). Next, an embodiment of the present invention may create atransport stream (TS) including the PES (S42030). The TS may indicate anMPEG-2 TS. A TS according to an embodiment of the present invention mayinclude PVR assist information for executing a trick play. The PVRassist information may mean information necessary for a receiver or aPVR apparatus to execute a trick play of video data. The PVR assistinformation has been previously described in detail with reference toFIG. 34. PVR assist information according to an embodiment of thepresent invention may include tier number information and/or maximumtemporal identification information. The tier number information mayindicate a tier number having a value obtained by adding 1 to a temporalidentification information value of a picture different from a RAPpicture and the maximum temporal identification information may indicatea maximum temporal identification information value of a video streamincluding encoded video data. Maximum temporal identificationinformation according to an embodiment of the present invention may benamed max_temporal_id or PVR_assist_max_temporal_id. The maximumtemporal identification information has been previously described indetail with reference to FIGS. 32, 35, 36, 37, and 40. The tier numbermay be used to signal a temporal sub-layer. The tier number may indicatedependency between pictures. For HEVC, the tier number may be used tosignal a temporal sub-layer in a similar manner to the temporalidentification information. The tier number information may be namedPVR_assist_tier_pic_num. The tier number information has been previouslydescribed in detail with reference to FIGS. 34, 35, 36, 39, and 40.Next, an embodiment of the present invention may transmit the created TS(S42040). An embodiment of the present invention may transmit a createdbroadcast signal through at least one selected from among a terrestrialbroadcasting network, a cable network, and an Internet network.According to another embodiment of the present invention, a videoelementary stream (ES) may include one or more temporal sub-layers andeach temporal sub-layer may indicate a group of pictures. A NAL unitheader including encoded video data according to an embodiment of thepresent invention may include temporal identification plus information.The temporal identification plus information may indicate a valueobtained by adding 1 to a value of temporal identification informationand the temporal identification information may include information foridentifying a temporal sub-layer. Temporal identification plusinformation according to an embodiment of the present invention may beused to identify a temporal sub-layer. The temporal sub-layer may benamed a temporal sub-layer, the temporal identification information maybe named a temporal id, and the temporal identification plus informationmay be named nuh_temporal_id_plus1. According to an embodiment of thepresent invention, PVR assist information may include maximum temporalidentification information indicating a maximum temporal identificationinformation value of a video elementary stream (ES). A video streamencoded by HEVC may have several temporal sub-layers and each temporalsub-layer may be identified by temporal identification information.Maximum temporal identification information according to an embodimentof the present invention may mean temporal identification information ofa temporal sub-layer having maximum temporal identification informationamong several temporal sub-layers. According to an embodiment of thepresent invention, PVR assist information may include temporalidentification flag information indicating whether maximum temporalidentification information is included. The temporal identification flaginformation may be provided for every RAP. The temporal identificationflag information may be named PVR_assist_temporal_id_info_present_flag.The temporal identification flag information may have a value of 1 in acase in which the maximum temporal identification information isincluded in the PVR assist information. For an AVC stream, the temporalidentification flag information may have a value of 0. An embodiment ofthe present invention may signal maximum temporal identificationinformation every RAP since temporal identification flag information isprovided for every RAP. Consequently, an embodiment of the presentinvention may signal maximum X speed information of a trick play everyRAP, which has been previously described in detail with reference toFIGS. 35 and 40.

According to another embodiment of the present invention, a tier numberindicated by the above-described tier number information may have avalue of 0 for a RAP picture. A tier number according to an embodimentof the present invention may be decided every picture constituting avideo stream. According to an embodiment of the present invention, atier number may have a value of 0 for a RAP picture. A RAP pictureaccording to an embodiment of the present invention may mean an HEVCDVB_RAP picture.

According to another embodiment of the present invention, maximumtemporal identification information may be used to provide informationregarding speed of a trick play. The maximum temporal identificationinformation may signal information regarding the maximum X speed of atrick play. An embodiment of the present invention may signal an X speedof a trick play corresponding to each piece of temporal identificationinformation. An embodiment of the present invention may inform a user ofinformation regarding a serviceable maximum X speed by signaling themaximum temporal identification information, decide the X speed of thetrick play according to a request of the user, and provide the decided Xspeed of the trick play to the user. According to an embodiment of thepresent invention, the maximum temporal identification information mayhave a value of any one selected from among 0 to 6. According to anotherembodiment of the present invention, therefore, a temporalidentification information value may match with a tier number within aconventionally defined range of the tier number in a case in which thetemporal identification information value matches with the tier numberone to one. Conventionally, the tier number is defined from 0 to 7,which has been previously described in detail with reference to FIGS. 35and 40.

According to another embodiment of the present invention, theabove-described PVR assist information may be included in an adaptationfield of a TS. The adaptation field, which is a field existing between aheader and a payload of a TS packet, may include data. According to anembodiment of the present invention, the adaptation field may include aprivate data byte field and the private data byte field may include PVRassist information. The private data byte field may be included in theadaptation field and may include several data fields. One of theabove-described several data fields may include PVR assist information.

According to another embodiment of the present invention, theabove-described PVR assist information may include segment info flaginformation indicating existence or nonexistence of informationregarding a segment to which a picture belongs, which has beenpreviously described in detail with reference to FIG. 34.

According to another embodiment of the present invention, theabove-described PVR assist information may include segment identifierinformation indicating an id of a segment to which a picture belongs,which has been previously described in detail with reference to FIG. 34.

According to another embodiment of the present invention, theabove-described PVR assist information may include program identifierinformation indicating an id of a program to which a picture belongs,which has been previously described in detail with reference to FIG. 34.

According to another embodiment of the present invention, theabove-described PVR assist information may include at least one selectedfrom between segment start flag information for identifying a picturehaving a first presentation order in each segment and segment end flaginformation for identifying a picture having a last presentation orderin each segment, which has been previously described in detail withreference to FIG. 34.

According to a further embodiment of the present invention, theabove-described PVR assist information may include at least one selectedfrom between program start flag information for identifying a picturehaving a first presentation order in each program and program end flaginformation for identifying a picture having a last presentation orderin each program, which has been previously described in detail withreference to FIG. 34.

FIG. 43 is a view showing the structure of a broadcast signal receivingapparatus according to an embodiment of the present invention.

A broadcast signal receiving apparatus 43010 according to an embodimentof the present invention may include a tuner 43020, a first extractionunit 43030, a second extraction unit 43040, and/or a decoder 43050.

The tuner may receive a transport stream (TS). The TS may include PVRassist information for executing a trick play. The PVR assistinformation may include tier number information and/or maximum temporalidentification information. The above-described tier number informationmay indicate a tier number having a value obtained by adding 1 to atemporal identification information value of a picture different from aRAP picture and the above-described maximum temporal identificationinformation may indicate a maximum temporal identification informationvalue of a video stream including encoded video data, which has beenpreviously described in detail with reference to FIG. 42.

The first extraction unit may extract a packetized elementary stream(PES) from the received TS.

The second extraction unit may extract a video elementary stream (ES)from the extracted PES.

The decoder may decode the extracted video elementary stream (ES).

Components of a broadcast signal receiving apparatus according to anembodiment of the present invention shown in this figure having the samenames as those of the broadcast signal receiving apparatus shown in FIG.38 may perform the same functions as those of the broadcast signalreceiving apparatus shown in FIG. 38.

Components of a broadcast signal receiving apparatus according to anembodiment of the present invention shown in this figure correspondingto the procedures of the broadcast signal transmitting method shown inFIG. 42 may perform functions corresponding to the procedures of thebroadcast signal transmitting method shown in FIG. 42.

While the present invention has been described with reference toseparate drawings for the convenience of description, a new embodimentmay be implemented by combining embodiments illustrated in therespective drawings. As needed by those skilled in the art, designing acomputer-readable recording medium, in which a program for implementingthe above-described embodiments is recorded, is within the scope of thepresent invention.

The apparatus and method according to the present invention may not belimitedly applied to the constructions and methods of the embodiments aspreviously described; however, all or some of the embodiments may beselectively combined to achieve various modifications.

Meanwhile, the control method of the mobile device according to thepresent specification may be implemented as code that can be written ona processor-readable recording medium and thus read by a processorprovided in the camera or the vehicle. The processor-readable recordingmedium may be any type of recording device in which data is stored in aprocessor-readable manner. The processor-readable recording medium mayinclude, for example, a read only memory (ROM), a random access memory(RAM), a compact disc read only memory (CD-ROM), a magnetic tape, afloppy disc, and an optical data storage device and may be implementedin the form of a carrier wave transmitted over the Internet. Inaddition, the processor-readable recording medium may be distributedover a plurality of computer systems connected to a network such thatprocessor-readable code is written thereto and executed therefrom in adecentralized manner.

It will be apparent that, although the preferred embodiments have beenshown and described above, the present specification is not limited tothe above-described specific embodiments, and various modifications andvariations can be made by those skilled in the art to which the presentinvention pertains without departing from the gist of the appendedclaims. Thus, it is intended that the modifications and variationsshould not be understood independently of the technical spirit orprospect of the present specification.

In addition, the present specification describes both a device inventionand a method invention, and descriptions of both the inventions may becomplementarily applied as needed.

MODE FOR INVENTION

Various embodiments for carrying out the invention have been describedin the best mode for carrying out the invention.

INDUSTRIAL APPLICABILITY

The present invention may be used in the broadcasting industry.

The invention claimed is:
 1. A method of transmitting a broadcastsignal, the method comprising: encoding video data to create a videoelementary stream, wherein the video elementary stream includes atemporal sub layer for supporting temporal scalability, wherein thetemporal sub layer is identified by a temporal identifier; creating apacketized elementary stream (PES) comprising the video elementarystream; creating a transport stream (TS) including the created PES,wherein the TS comprises PVR (Personal Video Recorder) assistinformation for executing a trick play, wherein the PVR assistinformation comprises temporal identifier flag information indicatingwhether maximum temporal identification information is present in thePVR assist information, wherein the PVR assist information comprisestier number information and the maximum temporal identificationinformation, wherein the tier number information indicates a tier numberobtained by using the temporal identifier of a picture in the temporalsub layer and the maximum temporal identification information indicatesa maximum temporal identifier of the video elementary stream comprisingthe encoded video data, and wherein the maximum temporal identificationinformation is used for providing speeds of the trick play supportedfrom the video elementary stream; and transmitting the created TS. 2.The method of claim 1, wherein the tier number is 0 when the picture isa Random Access Point (RAP) picture and the tier number is equal to thetemporal identifier of the picture plus 1 when the picture is differentfrom the RAP picture, and wherein the temporal identifier is signaled bya nuh_temporal_id_plus1 field in a Network Abstraction Layer (NAL) unitcarrying the picture of the temporal sub layer.
 3. The method of claim1, wherein the temporal identifier flag information is provided when thepicture is a Random Access Point (RAP) picture.
 4. The method of claim1, wherein the PVR assist information is contained in an adaptationfield of the TS.
 5. The method of claim 1, wherein the PVR assistinformation comprises segmentation info flag information indicatingexistence or nonexistence of information regarding a segment to which apicture belongs.
 6. The method of claim 5, wherein the PVR assistinformation comprises segment identifier information indicating anidentifier (ID) of a segment to which a picture belongs.
 7. The methodof claim 1, wherein the PVR assist information comprises additional tiernumber information indicating an additional tier number, wherein theadditional tier number indicates dependencies of pictures which have 0as a value of the temporal identifier, wherein a higher speed trick playis provided by decoding pictures having 0 as a value of the temporalidentifier and having a specific additional tier number, and wherein alower speed trick play is provided by decoding pictures having 0 as avalue of the temporal identifier and pictures having 1 or more as avalue of the temporal identifier.
 8. The method of claim 1, wherein thetrick play is provided by only parsing a nuh_temporal_id_plus1 field ina Network Abstraction Layer (NAL) unit carrying the picture of thetemporal sub layer without parsing the tier number information.
 9. Themethod of claim 1, wherein the PVR assist information comprises framenumber information indicating a number of frames existing between intraframes.
 10. An apparatus of receiving a broadcast signal, the apparatuscomprising: a tuner configured to receive a transport stream (TS)including a packetized elementary stream (PES) comprising a videoelementary stream, wherein the video elementary stream includes atemporal sub layer for supporting temporal scalability, wherein thetemporal sub layer is identified by a temporal identifier, wherein theTS comprises PVR (Personal Video Recorder) assist information forexecuting a trick play, wherein the PVR assist information comprisestemporal identifier flag information indicating whether maximum temporalidentification information is present in the PVR assist information,wherein the PVR assist information comprises tier number information andthe maximum temporal identification information, wherein the tier numberinformation indicates a tier number obtained by using the temporalidentifier of a picture in the temporal sub layer and the maximumtemporal identification information indicates a maximum temporalidentifier of the video elementary stream comprising encoded video data,wherein the maximum temporal identification information is used forproviding speeds of the trick play supported from the video elementarystream; a PES extractor configured to extract the packetized elementarystream (PES) from the TS; a video elementary stream extractor configuredto extract the video elementary stream from the extracted PES; and adecoder configured to decode the extracted video elementary stream usingthe tier number information and the maximum temporal identificationinformation.
 11. The apparatus of claim 10, wherein the tier number is 0when the picture is a Random Access Point (RAP) picture and the tiernumber is equal to the temporal identifier of the picture plus 1 whenthe picture is different from the RAP picture, and wherein the temporalidentifier is signaled by a nuh_temporal_id_plus1 field in a NetworkAbstraction Layer (NAL) unit carrying the picture of the temporal sublayer.
 12. The apparatus of claim 10, wherein the temporal identifierflag information is provided when the picture is a Random Access Point(RAP) picture.
 13. The apparatus of claim 10, wherein the PVR assistinformation is contained in an adaptation field of the TS.
 14. Theapparatus of claim 10, wherein the PVR assist information comprisessegmentation info flag information indicating existence or nonexistenceof information regarding a segment to which a picture belongs.
 15. Theapparatus of claim 14, wherein the PVR assist information comprisessegment identifier information indicating an identifier (ID) of asegment to which a picture belongs.
 16. The apparatus of claim 10,wherein the PVR assist information comprises additional tier numberinformation indicating an additional tier number, wherein the additionaltier number indicates dependencies of pictures which have 0 as a valueof the temporal identifier, wherein a higher speed trick play isprovided by decoding pictures having 0 as a value of the temporalidentifier and having a specific additional tier number, and wherein alower speed trick play is provided by decoding pictures having 0 as avalue of the temporal identifier and pictures having 1 or more as avalue of the temporal identifier.
 17. The apparatus of claim 10, whereinthe trick play is provided by only parsing a nuh_temporal_id_plus1 fieldin a Network Abstraction Layer (NAL) unit carrying the picture of thetemporal sub layer without parsing the tier number information.
 18. Theapparatus of claim 10, wherein the PVR assist information comprisesframe number information indicating a number of frames existing betweenintra frames.